answers (anticipation guide and lesson 8-1) © glencoe/mcgraw-hill, a division of the mcgraw-hill...

21
Answers Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Chapter 8 A1 Glencoe Algebra 1 Chapter Resources Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. NAME DATE PERIOD Chapter 8 3 Glencoe Algebra 1 Anticipation Guide Factoring Before you begin Chapter 8 • Read each statement. • Decide whether you Agree (A) or Disagree (D) with the statement. Write A or D in the first column OR if you are not sure whether you agree or disagree, write NS (Not Sure). After you complete Chapter 8 Reread each statement and complete the last column by entering an A or a D. • Did any of your opinions about the statements change from the first column? For those statements that you mark with a D, use a piece of paper to write an example of why you disagree. 8 Step 1 Step 2 STEP 1 A, D, or NS Statement STEP 2 A or D 1. A monomial is in factored form when it is expressed as the product of prime numbers and variables, and no variable has an exponent greater than 1. A 2. The greatest common factor (GCF) of two or more monomials is the product of their unique factors when each monomial is written in factored form. A 3. Any two numbers that have a greatest common factor of 1 are said to be relatively prime. A 4. If the product of any two factors is 0, then at least one of the factors must equal 0. A 5. A quadratic trinomial has a degree of 4. D 6. To solve an equation such as x 2 = 8 + 2x, take the square root of both sides. D 7. The polynomial 3r 2 - r - 2 can not be factored because the coefficient of r 2 is not 1. D 8. The polynomial t 2 + 16 is not factorable. A 9. The numbers 16, 64, and 121 are perfect squares. A Answers (Anticipation Guide and Lesson 8-1) Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. NAME DATE PERIOD Lesson 8-1 Chapter 8 5 Glencoe Algebra 1 Study Guide and Intervention Monomials and Factoring 8-1 Factor Monomials A monomial is in factored form when it is expressed as the product of prime numbers and variables, and no variable has an exponent greater than 1. Factor each monomial completely. a. 42a 3 42a 3 = 2 21 a a a 42 = 21 2, and a 3 = a a a = 2 3 7 a a a 21 = 3 7 Thus, 42a 3 in factored form is 2 3 7 a a a. b. -40x 2 y 3 -40x 2 y 3 = -1 40 x 2 y 3 Express -40 as -1 40. = -1 2 20 x x y y y 40 = 20 2, x 2 = x x, and y 3 = y y y = -1 2 2 10 x x y y y 20 = 10 2 = -1 2 2 2 5 x x y y y 10 = 5 2 Thus, -40x 2 y 3 in factored form is -1 2 2 2 5 x x y y y. Exercises Factor each monomial completely. 1. 32x 2 2. 18m 2 n 3. 49a 3 b 2 2 2 2 2 2 x x 2 3 3 m m n 7 7 a a a b b 4. 18y 3 5. -9h 3 jk 2 6. -8d 2 2 3 3 y y y -1 3 3 h h h j k k -1 2 2 2 d d 7. 66q 3 r 3 8. 140x 2 y 4 z 9. ab 2 f 2 2 3 11 q q q r r r 2 2 5 7 x x y y y y z -1 a b b f f 10. -17t 11. 625jk 2 12. 47wx 3 yz 2 -1 17 t 5 5 5 5 j k k 47 w x x x y z z 13. 12r 4 14. -38a 2 b 15. 4mp 2 2 3 r r r r -1 2 19 a a b 2 2 m p Example

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Page 1: Answers (Anticipation Guide and Lesson 8-1) © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers Chapter 8 A3 Glencoe Algebra 1 Copyright © Glencoe/McGraw-Hill,

Answers

Co

pyri

gh

t ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f T

he M

cG

raw

-Hill C

om

pan

ies,

Inc.

Chapter 8 A1 Glencoe Algebra 1

Chapter Resources

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

8

3

Gle

ncoe A

lgeb

ra 1

An

tici

pati

on

Gu

ide

Facto

rin

g

B

efo

re y

ou

beg

in C

ha

pte

r 8

R

ead

each

sta

tem

en

t.

D

eci

de w

heth

er

you

Agre

e (

A)

or

Dis

agre

e (

D)

wit

h t

he s

tate

men

t.

W

rite

A o

r D

in

th

e f

irst

colu

mn

OR

if

you

are

not

sure

wh

eth

er

you

agre

e o

r d

isagre

e,

wri

te N

S (

Not

Su

re).

Aft

er y

ou

com

ple

te C

ha

pte

r 8

R

ere

ad

each

sta

tem

en

t an

d c

om

ple

te t

he l

ast

colu

mn

by e

nte

rin

g a

n A

or

a D

.

D

id a

ny o

f you

r op

inio

ns

abou

t th

e s

tate

men

ts c

han

ge f

rom

th

e f

irst

colu

mn

?

F

or

those

sta

tem

en

ts t

hat

you

mark

wit

h a

D,

use

a p

iece

of

pap

er

to w

rite

an

exam

ple

of

wh

y y

ou

dis

agre

e.

8 Ste

p 1

Ste

p 2

ST

EP

1A

, D

, o

r N

SS

tate

men

tS

TE

P 2

A o

r D

1.

A m

on

om

ial

is i

n f

act

ore

d f

orm

wh

en

it

is e

xp

ress

ed

as

the

pro

du

ct o

f p

rim

e n

um

bers

an

d v

ari

able

s, a

nd

no v

ari

able

has

an

exp

on

en

t gre

ate

r th

an

1.

A

2.

Th

e g

reate

st c

om

mon

fact

or

(GC

F)

of

two o

r m

ore

mon

om

ials

is

th

e p

rod

uct

of

their

un

iqu

e f

act

ors

wh

en

each

mon

om

ial

is

wri

tten

in

fact

ore

d f

orm

.A

3.

An

y t

wo n

um

bers

th

at

have a

gre

ate

st c

om

mon

fact

or

of

1 a

re

said

to b

e r

ela

tively

pri

me.

A

4.

If t

he p

rod

uct

of

an

y t

wo f

act

ors

is

0,

then

at

least

on

e o

f th

e

fact

ors

mu

st e

qu

al

0.

A

5.

A q

uad

rati

c tr

inom

ial

has

a d

egre

e o

f 4.

D

6.

To s

olv

e a

n e

qu

ati

on

su

ch a

s x

2 =

8 +

2x,

tak

e t

he s

qu

are

root

of

both

sid

es.

D

7.

Th

e p

oly

nom

ial

3r2

- r

- 2

can

not

be f

act

ore

d b

eca

use

th

e

coeff

icie

nt

of

r2 i

s n

ot

1.

D

8.

Th

e p

oly

nom

ial

t2 +

16 i

s n

ot

fact

ora

ble

. A

9.

Th

e n

um

bers

16,

64,

an

d 1

21 a

re p

erf

ect

squ

are

s.A

Answers (Anticipation Guide and Lesson 8-1)

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Lesson 8-1

Ch

ap

ter

8

5

Gle

ncoe A

lgeb

ra 1

Stu

dy

Gu

ide a

nd

In

terv

en

tio

n

Mo

no

mia

ls a

nd

Facto

rin

g

8-1

Fact

or

Mo

no

mia

ls A

mon

om

ial

is i

n f

act

ore

d f

orm

wh

en

it

is e

xp

ress

ed

as

the p

rod

uct

of

pri

me n

um

bers

an

d v

ari

able

s, a

nd

no v

ari

able

has

an

exp

on

en

t gre

ate

r th

an

1.

F

acto

r e

ach

mo

no

mia

l co

mp

lete

ly.

a.

42a

3

42a

3 =

2

21

a

a

a

42 =

21

2,

and a

3 =

a

a

a

= 2

3

7

a

a

a

21 =

3

7

Th

us,

42a

3 i

n f

act

ore

d f

orm

is

2

3

7

a

a

a.

b. -

40

x2y

3

-40x

2y

3 =

-1

40 x

2 y

3

Expre

ss -

40 a

s -

1

40

.

= -

1

2

20

x

x

y

y

y

40 =

20

2,

x2 =

x

x,

and y

3 =

y

y

y

= -

1

2

2

10

x

x

y

y

y

20 =

10

2

=

-1

2

2

2

5

x

x

y

y

y

10 =

5

2

Th

us,

-40

x2y

3 i

n f

act

ore

d f

orm

is

-1

2

2

2

5

x

x

y

y

y.

Exerc

ises

Fa

cto

r e

ach

mo

no

mia

l co

mp

lete

ly.

1. 32x

2

2. 18m

2n

3. 49

a3b

2

2

2

2

2

2

x

x

2

3

3

m

m

n

7

7

a

a

a

b

b

4. 18y

3

5. -

9h

3jk

2

6. -

8d

2

2

3

3

y

y

y

-

1

3

3

h

h

h

j

k

k

-

1

2

2

2

d

d

7. 66q

3r3

8. 140x

2y

4z

9. –

ab

2f

2

2 3

1

1 q

q

q

r r r

2 2

5

7

x

x

y

y

y

y

z

-

1 a

b

b

f f

10. -

17t

11. 625jk

2

12. 47w

x3yz2

-

1 1

7 t

5 5

5

5

j k

k

47 w

x

x

x

y

z

z

13. 12r4

14. -

38a

2b

15. 4

mp

2

2

3

r

r

r

r

-

1

2

19

a

a

b

2

2

m

p

Exam

ple

Page 2: Answers (Anticipation Guide and Lesson 8-1) © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers Chapter 8 A3 Glencoe Algebra 1 Copyright © Glencoe/McGraw-Hill,

Co

pyrig

ht ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f Th

e M

cG

raw

-Hill C

om

pan

ies, In

c.

Chapter 8 A2 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

8

6

Gle

ncoe A

lgeb

ra 1

Stu

dy

Gu

ide a

nd

In

terv

en

tio

n

(con

tin

ued

)

Mo

no

mia

ls a

nd

Facto

rin

g

Greatest C

om

mo

n F

acto

r

Th

e p

rod

uct

of

the c

om

mon

pri

me f

act

ors

is

call

ed

th

e

gre

ate

st c

om

mon

fact

or

(GC

F)

of

the n

um

bers

. T

he g

reate

st c

om

mon

fact

or

is t

he g

reate

st

nu

mber

that

is a

fact

or

of

both

ori

gin

al

nu

mbers

.

If t

wo o

r m

ore

in

tegers

or

mon

om

ials

have n

o c

om

mon

pri

me f

act

ors

, th

eir

GC

F i

s 1 a

nd

th

e

inte

gers

or

mon

om

ials

are

said

to b

e r

ela

tiv

ely

prim

e.

F

ind

th

e G

CF

of

16xy

2z

2 a

nd

72xyz

3.

16

xy

2z2

= 2 !

2 !

2 !

2 !

x !

y !

y !

z !

z

72xyz3

= 2 !

2 !

2 !

3 !

3 !

x !

y !

z !

z !

z

Th

e G

CF

of

16

xy

2z2

an

d 7

2xyz3

is

2 !

2 !

2 !

x !

y !

z !

z o

r 8

xyz2

.

Exerc

ises

Fin

d t

he G

CF

of

ea

ch

set

of

mo

no

mia

ls.

1. 49x,

343

x2

2. 4

a7b

, 28a

b49

x

4ab

3. 96y,

12

x,

8y

4. 12a

, 18a

bc

4

6a

5. 28y

2,

35xy,

49x

2yz

6. 2m

2p

, 12

mp

2,

18m

p7

y

2m

p

7. 12x

2,

32x

2yz,

60xy

2

8. 18a

3b

2,

36a

3b

2

4x

18

a3b

2

9. 15m

n2,

30

m3n

2,

90m

3

10. 2x

2y,

9x

2y

3,

18xy

2

15

m

xy

11. a

4b,

8a

3b

2

12. a

b2,

5a

4b

2,

10

b3

a3b

b

2

13. 2

x2y

2,

8xy

4,

12x

2y

14. 6

a2b

5,

15

a3b

4

2xy

3a

2b

4

15. 21a

4b

7f2

, 84a

3b

4,

28a

5b

2f3

16. 13x

2y

5,

5xy

3,

x4y

7

a3b

2

xy

8-1 Exam

ple

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Lesson 8-1

Ch

ap

ter

8

7

Gle

ncoe A

lgeb

ra 1

Sk

ills

Pra

ctic

e

Mo

no

mia

ls a

nd

Facto

rin

g

Fa

cto

r e

ach

mo

no

mia

l co

mp

lete

ly.

1. 10a

4 2 �

5 �

a �

a �

a �

a

2.

-27x

3y

2

-1 �

3 �

3 �

3 ·

x �

x �

x �

y �

y

3. 28p

r2 2 �

2 �

7 �

p �

r �

r

4. 44m

2n

p3 2

� 2

� 1

1 �

m �

m �

n �

p �

p �

p

5. 9

x3y

2 3 �

3 �

x �

x �

x �

y �

y

6.

-17

ab

2f

-1 �

17 �

a �

b �

b �

f

7. 42g

2 2 �

3 �

7 �

g �

g

8. 36

tu2 2 �

2 �

3 �

3 �

t �

u �

u

9.

-4a

-

1 �

2 �

2 �

a

10.

-10x

4yz2

-

1 �

2 �

5 �

x �

x �

x �

x �

y �

z �

z

Fin

d t

he G

CF

of

ea

ch

set

of

mo

no

mia

ls.

11. 16f,

21a

b2 1

12. 18t,

48t4

6

t

13. 32xyz,

48xy

4 16

xy

14. 12m

3p

2,

44m

p3 4m

p2

15. 4

q2r2

t2,

9q

3r3

t3 q

2r2

t2

16. 14

ab

5,

7a

2b

3c

7ab

3

17. 51xyz2

, 68x

2yz2

17xyz

2

18. 12

t7u

3,

18t3

u7 6t3

u3

19. 11

a4b

3,

44a

2b

5 11

a2b

3

20. 18r3

t, 2

6qr2

t4 2

r2t

8-1

Answers (Lesson 8-1)

Page 3: Answers (Anticipation Guide and Lesson 8-1) © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers Chapter 8 A3 Glencoe Algebra 1 Copyright © Glencoe/McGraw-Hill,

Answers

Co

pyri

gh

t ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f T

he M

cG

raw

-Hill C

om

pan

ies,

Inc.

Chapter 8 A3 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

8

8

Gle

ncoe A

lgeb

ra 1

Practi

ce

Mo

no

mia

ls a

nd

Facto

rin

g

Fa

cto

r e

ach

mo

no

mia

l co

mp

lete

ly.

1. 30d

5

2. -

72m

p

2

� 3

� 5

� d

� d

� d

� d

� d

-

1 �

2 �

2 �

2 �

3 �

3 �

m �

p

3. 81b

2c3

4. 145

abc3

3

� 3

� 3

� 3

� b

� b

� c

� c

� c

5

� 2

9 �

a �

b �

c �

c �

c

5. 168n

q2r

6. -

121

x2yz2

2

� 2

� 2

� 3

� 7

� n

� q

� q

� r

-

1 �

11 �

11 �

x �

x �

y �

z �

z

7. -

14f

2g

2

8. -

77

w4

-

1 �

2 �

7 �

f �

f �

g �

g

-1 �

7 �

11 �

w �

w �

w �

w

Fin

d t

he G

CF

of

ea

ch

set

of

mo

no

mia

ls.

9. 24fg

5,

56

f 3g 8

fg

10. 72r2

t2,

36

rt3 36

rt2

11. 15a

2b

, 35

ab

2 5

ab

12. 28k

3n

2,

45p

r2 1

13. 40xy

2,

56x

3y

2,

124x

2y

3 4

xy

2

14. 88a

3d

, 40a

2d

2,

32

a2d

8a

2d

15. G

EO

METR

Y T

he a

rea o

f a r

ect

an

gle

is

84 s

qu

are

in

ches.

Its

len

gth

an

d w

idth

are

both

wh

ole

nu

mbers

.

a.

Wh

at

is t

he m

inim

um

peri

mete

r of

the r

ect

an

gle

? 38 i

n.

b.

Wh

at

is t

he m

axim

um

peri

mete

r of

the r

ect

an

gle

? 170 i

n.

16. R

EN

OV

ATIO

N M

s. B

axte

r w

an

ts t

o t

ile a

wall

to s

erv

e a

s a s

pla

shgu

ard

above a

basi

n

in t

he b

ase

men

t. S

he p

lan

s to

use

equ

al-

sized

til

es

to c

over

an

are

a t

hat

measu

res

48 i

nch

es

by 3

6 i

nch

es.

a.

Wh

at

is t

he m

axim

um

-siz

e s

qu

are

til

e M

s. B

axte

r ca

n u

se a

nd

not

have t

o c

ut

an

y o

f

the t

iles?

12-i

n.

sq

uare

b.

How

man

y t

iles

of

this

siz

e w

ill

she n

eed

? 12

8-1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Lesson 8-1

Ch

ap

ter

8

9

Gle

ncoe A

lgeb

ra 1

Wo

rd

Pro

ble

m P

racti

ce

Mo

no

mia

ls a

nd

Facto

rin

g

1. M

ATH

GA

MES

M

rs.

Jen

son

’s c

lass

is

pla

yin

g “

Gu

ess

th

e M

on

om

ial.

” O

ne

stu

den

t d

isp

lays

fact

ors

of

the s

ecr

et

mon

om

ial,

an

d t

he t

eam

tri

es

to g

uess

the m

on

om

ial.

Wh

en

it

is J

am

es’

tu

rn,

he

sees

that

the s

ecr

et

mon

om

ial

is 2

10x

2y

2.

Wh

ich

of

the f

oll

ow

ing c

ard

s sh

ou

ld h

e

dis

pla

y s

o h

is t

eam

gu

ess

es

the c

orr

ect

mon

om

ial?

3x

5x

7y

11y

13z

17z

19z

O

rder

may v

ary

:

2

� 3

� 5

� 7

�x �

x�

y�

y

2. PA

RTY

FA

VO

RS

B

all

oon

s co

me i

n

pack

ages

of

18 a

nd

part

y h

ats

com

e i

n

pack

ages

of

8.

Jeff

wan

ts t

o h

ave t

he

sam

e n

um

ber

of

ball

oon

s an

d h

ats

. W

hat

is t

he f

ew

est

pack

ages

of

ball

oon

s an

d

hats

th

at

he n

eed

s to

bu

y s

o h

e h

as

no

hats

or

ball

oon

s le

ft o

ver?

4 p

ackag

es

of

ballo

on

s a

nd

9 p

ackag

es o

f h

ats

3. PA

CK

AG

ING

C

olo

r W

heel

pri

nte

r in

k

com

pan

y w

an

ts t

o d

esi

gn

a n

ew

cart

on

in

wh

ich

to p

ack

pri

nte

r in

k c

art

rid

ges

for

ship

men

t to

sto

res.

Cart

rid

ge b

oxes

are

7 i

nch

es

lon

g a

nd

3 i

nch

es

wid

e.

Wh

at

are

th

e d

imen

sion

s of

the s

mall

est

squ

are

-bott

om

cart

on

th

at

wil

l h

old

th

e

cart

rid

ge b

oxes

wit

hou

t extr

a s

pace

?

21 i

n.

by 2

1 i

n.

4. M

ATH

EM

ATIC

IAN

S A

Gre

ek

math

em

ati

cian

an

d a

stro

nom

er

nam

ed

Era

tost

hen

es

create

d a

way t

o s

ep

ara

te

pri

me n

um

bers

fro

m c

om

posi

te n

um

bers

.

His

meth

od

is

kn

ow

n a

s th

e S

ieve o

f

Era

tost

hen

es.

It

pro

ceed

s as

foll

ow

s.

So

urc

e:

Math

Foru

m

Recr

eate

th

e S

ieve o

f E

rato

sth

en

es

to

fin

d t

he f

irst

11 p

rim

e n

um

bers

. 2,

3,

5,

7,

11,

13,

17,

19,

23,

29,

31

5. R

EPA

IRS

Heid

i w

an

ts t

o r

ep

lace

th

e

floor

in h

er

16-f

oot

by 1

8-f

oot

rect

an

gu

lar

dan

ce s

tud

io.

Sh

e w

an

ts t

o u

se s

qu

are

wood

til

es,

an

d s

he d

oes

not

wan

t to

have

to c

ut

an

y o

f th

e t

iles

nor

leave a

ny g

ap

s.

a.

Su

pp

ose

th

e f

loori

ng c

om

pan

y c

an

use

an

y s

ize t

ile.

Wh

at

is t

he l

arg

est

squ

are

til

e t

hat

Heid

i ca

n u

se f

or

the

new

flo

or?

2 f

eet

by 2

feet

b.

If H

eid

i fi

rst

kn

ock

s ou

t a w

all

an

d

incr

ease

s th

e s

tud

io t

o 2

4 f

eet

by

18 f

eet,

wh

at

is t

he l

arg

est

squ

are

til

e

she c

an

use

for

the n

ew

flo

or?

6 f

oo

t b

y 6

fo

ot

8-1

Write

num

bers

1 t

o 5

0.

Sin

ce 1

is n

either

prim

e n

or

com

posite,

ignore

1.

Circle

the n

um

ber

2,

and t

hen c

ross o

ff e

very

num

ber

that

is d

ivis

ible

by 2

.

Circle

the n

ext

num

ber

that

is n

ot

cro

ssed o

ff,

3,

and c

ross o

ff a

ll m

ultip

les o

f 3.

Circle

the n

ext

num

ber

that

is n

ot

cro

ssed o

ff,

5,

and c

ross o

ff t

he

multip

les o

f 5,

etc

Answers (Lesson 8-1)

Page 4: Answers (Anticipation Guide and Lesson 8-1) © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers Chapter 8 A3 Glencoe Algebra 1 Copyright © Glencoe/McGraw-Hill,

Co

pyrig

ht ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f Th

e M

cG

raw

-Hill C

om

pan

ies, In

c.

Chapter 8 A4 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

8

10

Gle

ncoe A

lgeb

ra 1

En

rich

men

t

Fin

din

g t

he G

CF b

y E

uclid

’s A

lgo

rith

mF

ind

ing t

he g

reate

st c

om

mon

fact

or

of

two l

arg

e n

um

bers

can

tak

e a

lo

ng t

ime u

sin

g p

rim

e f

act

ori

zati

on

s. T

his

meth

od

can

be a

void

ed

by

usi

ng E

ucl

id’s

Alg

ori

thm

as

show

n i

n t

he f

oll

ow

ing e

xam

ple

.

F

ind

th

e G

CF

of

209 a

nd

532.

Div

ide t

he g

reate

r n

um

ber,

532,

by t

he l

ess

er,

209.

Th

e d

ivis

or,

19,

is t

he G

CF

of

209 a

nd

532.

Su

pp

ose

th

e G

CF

of

two n

um

bers

is

fou

nd

to b

e 1

. T

hen

th

e n

um

bers

are

said

to b

e r

ela

tiv

ely

prim

e.

Fin

d t

he G

CF

of

ea

ch

gro

up

of

nu

mb

ers b

y u

sin

g E

ucli

d’s

Alg

orit

hm

.

1. 187;

578 17

2. 1802;

106 106

3. 161;

943 23

4. 215;

1849 43

5. 1325;

3498 53

6. 3484;

5963 67

7. 33,5

83;

4257 473

8. 453;

484 1 (

rela

tively

pri

me)

9. 95;

209;

589 19

10. 518;

407;

851 37

11. 17a

2x

2z;

1615

axz2

17axz

12. 752

af 3

; 893

a3f 3

47af 3

13. 979

r2t2

; 495

rt3,

154

r3t3

11rt

2

14. 360

x5y

7;

328

xy;

568

x3y

3 8

xy

8-1 Exam

ple

Div

ide t

he r

em

ain

der

into

th

e d

ivis

or

above.

Rep

eat

this

pro

cess

u

nti

l th

e r

em

ain

der

is z

ero

. T

he l

ast

n

on

zero

rem

ain

der

is

the G

CF

.

2

209 � ����

����������

���� 532

__

__

418 1

114 � �

����������

�������

209

__

__

114 1

95 � �

����������

�������

114

__

_ 95 5

19 � �

����������

�� 95

__

_ 95

0

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Lesson 8-2

Ch

ap

ter

8

11

Gle

ncoe A

lgeb

ra 1

Stu

dy

Gu

ide a

nd

In

terv

en

tio

n

Usin

g t

he D

istr

ibu

tive P

rop

ert

y

Use

th

e D

istr

ibu

tive P

rop

ert

y t

o F

act

or

Th

e D

istr

ibu

tive P

rop

ert

y h

as

been

use

d

to m

ult

iply

a p

oly

nom

ial

by a

mon

om

ial.

It

can

als

o b

e u

sed

to e

xp

ress

a p

oly

nom

ial

in

fact

ore

d f

orm

. C

om

pare

th

e t

wo c

olu

mn

s in

th

e t

able

belo

w.

U

se t

he D

istr

ibu

tiv

e

Pro

perty

to

fa

cto

r 1

2mp

+ 8

0m

2.

Fin

d t

he G

CF

of

12m

p a

nd

80m

2.

12m

p =

2 �

2 �

3 �

m �

p

80

m2 =

2 �

2 �

2 �

2 �

5 �

m �

m

GC

F =

2 �

2 �

m o

r 4m

Wri

te e

ach

term

as

the p

rod

uct

of

the G

CF

an

d i

ts r

em

ain

ing f

act

ors

.

12

mp

+ 8

0m

2 =

4m

(3 �

p)

+ 4

m(2

� 2

� 5

� m

)

= 4

m(3

p)

+ 4

m(2

0m

)

= 4

m(3

p +

20m

)

Th

us

12

mp

+ 8

0m

2 =

4m

(3p

+ 2

0m

).

F

acto

r

6ax +

3ay +

2bx

+ by b

y g

ro

up

ing

.

6a

x +

3a

y +

2bx +

by

= (

6a

x +

3a

y)

+ (

2bx +

by)

= 3

a(2

x +

y)

+ b

(2x +

y)

= (

3a

+ b

)(2x +

y)

Ch

eck

usi

ng t

he F

OIL

meth

od

.

(3a

+ b

)(2

x +

y)

= 3

a(2

x)

+ (

3a

)(y)

+ (

b)(

2x)

+ (

b)(

y)

= 6

ax +

3a

y +

2bx +

by ✓

Exerc

ises

Fa

cto

r e

ach

po

lyn

om

ial.

1. 24x +

48y

2. 30

mp

2 +

m2p

- 6

p

3. q

4 -

18q

3 +

22

q

2

4(x

+ 2

y)

p(3

0m

p +

m2 -

6)

q(q

3 -

18q

2 +

22)

4. 9

x2 -

3x

5. 4

m +

6p

- 8

mp

6. 45

r3 -

15r2

3

x(3

x -

1)

2(2

m +

3p

- 4

mp

) 1

5r2

(3r -

1)

7. 14t3

- 4

2t5

- 4

9t4

8. 55p

2 -

11p

4 +

44

p5

9. 14y

3 -

28

y2 +

y

7

t3(2

- 6

t2 -

7t)

1

1p

2(5

- p

2 +

4p

3)

y(1

4y

2 -

28y +

1)

10. 4

x +

12x

2 +

16x

3

11. 4a

2b

+ 2

8a

b2 +

7a

b

12. 6y +

12x -

8z

4

x(1

+ 3

x +

4x

2)

ab

(4a +

28b

+ 7

) 2

(3y +

6x -

4z)

13. x

2 +

2x +

x +

2

14. 6

y2 -

4y +

3y -

2

15. 4

m2 +

4m

p +

3m

p +

3p

2

(

x +

1)(

x +

2)

(2

y +

1)(

3y -

2)

(4

m +

3p

)(m

+ p

)

16. 12a

x +

3xz

+ 4

ay +

yz

17. 12

a2 +

3a

- 8

a -

2

18. xa

+ y

a +

x +

y

(

3x +

y)(

4a

+ z

) (

4a +

1)(

3a

- 2

) (

x +

y)(

a +

1)

8-2

Exam

ple

1Exam

ple

2

Mu

ltip

lyin

gF

acto

rin

g

3(a

+ b

) =

3a

+ 3

b3

a +

3b

= 3

(a +

b)

x(y

- z

) =

xy -

xz

xy -

xz =

x(y

- z

)

6y(2

x +

1)

= 6

y(2

x)

+ 6

y(1

)

=

12

xy +

6y

12

xy +

6y =

6y(2

x)

+ 6

y(1

)

=

6y(2

x +

1)

Answers (Lesson 8-1 and Lesson 8-2)

Page 5: Answers (Anticipation Guide and Lesson 8-1) © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers Chapter 8 A3 Glencoe Algebra 1 Copyright © Glencoe/McGraw-Hill,

Answers

Co

pyri

gh

t ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f T

he M

cG

raw

-Hill C

om

pan

ies,

Inc.

Chapter 8 A5 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

8

12

Gle

ncoe A

lgeb

ra 1

Stu

dy

Gu

ide a

nd

In

terv

en

tio

n

(con

tin

ued

)

Usin

g t

he D

istr

ibu

tive P

rop

ert

y

So

lve E

qu

ati

on

s b

y F

act

ori

ng

T

he f

oll

ow

ing p

rop

ert

y,

alo

ng w

ith

fact

ori

ng,

can

be

use

d t

o s

olv

e c

ert

ain

equ

ati

on

s.

S

olv

e 9x

2 +

x =

0.

Th

en

ch

eck

th

e s

olu

tio

ns.

Wri

te t

he e

qu

ati

on

so t

hat

it i

s of

the f

orm

ab

= 0

.

9x

2 +

x =

0

Origin

al equation

x(9

x +

1) =

0

Facto

r th

e G

CF

of

9x

2 +

x,

whic

h is x

.

x =

0 or

9x +

1 =

0

Zero

Pro

duct

Pro

pert

y

x =

0 x

= -

1 −

9

Solv

e e

ach e

quation.

Th

e s

olu

tion

set

is {0

, -

1 −

9 } .

Ch

eck

S

ubst

itu

te 0

an

d -

1 −

9 f

or

x i

n t

he o

rigin

al

equ

ati

on

.

9x

2 +

x =

0

9x

2 +

x =

0

9(0

)2 +

0 "

0

9 (- 1

9 ) 2

+ (-

1 −

9 ) "

0

0 =

0 ✓

1

9 +

(- 1

9 ) "

0

0 =

0 ✓

So

lve e

ach

eq

ua

tio

n.

Ch

eck

yo

ur s

olu

tio

ns.

1. x(x

+ 3

) =

0

2. 3m

(m -

4) =

0

3. (r

- 3

)(r +

2) =

0

{

0, -

3}

{0,

4}

{-

2,

3}

4. 3

x(2

x -

1) =

0

5. (4

m +

8)(

m -

3) =

0

6. 5t2

= 2

5t

{

0,

1

2 }

{-

2,

3}

{0,

5}

7. (4

c +

2)(

2c -

7) =

0

8. 5p

- 1

5p

2 =

0

9. 4y

2 =

28y

{- 1

2 ,

7

2 }

{0,

1

3 }

{0,

7}

10. 12x

2 =

-6

x

11. (4

a +

3)(

8a

+ 7

) =

0

12. 8y =

12y

2

{- 1

2 ,

0}

{- 7

8 , - 3

4 }

{0,

2

3 }

13. x

2 =

-2

x

14. (6

y -

4)(

y +

3) =

0

15. 4m

2 =

4m

{-

2,

0}

{-

3,

2

3 }

{0,

1}

16. 12x =

3x

2

17. 12a

2 =

-3

a

18. (1

2a

+ 4

)(3a

- 1

) =

0

{

0,

4}

{- 1

4 ,

0}

{- 1

3 ,

1

3 }

8-2 Exam

ple

Exerc

ises

Zero

Pro

du

ct

Pro

pert

yF

or

any r

eal num

bers

a a

nd b

, if

ab

= 0

, th

en e

ither

a =

0,

b =

0,

or

both

a a

nd b

equal 0.

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Lesson 8-2

Ch

ap

ter

8

13

Gle

ncoe A

lgeb

ra 1

Sk

ills

Pra

ctic

e

Usin

g t

he D

istr

ibu

tive P

rop

ert

y

Fa

cto

r e

ach

po

lyn

om

ial.

1. 7

x +

49

2. 8

m -

6

7

(x +

7)

2(4

m -

3)

3. 5

a2 -

15

4. 10

q -

25q

2

5

(a2 -

3)

5q

(2 -

5q

)

5. 8

ax -

56a

6. 81r +

48

rt

8

a(x

- 7

) 3

r(2

7 +

16

t)

7. t2

h +

3t

8. a

2b

2 +

a

t

(th

+ 3

) a

(ab

2 +

1)

9. x +

x2y +

x3y

2

10. 3

p2r2

+ 6

pr +

p

x

(1 +

xy +

x2y

2)

p(3

pr2

+ 6

r +

1)

11. 4a

2b

2 +

16a

b +

12a

12. 10

h3n

3 -

2h

n2 +

14h

n

4

a(a

b2 +

4b

+ 3

) 2

hn

(5h

2n

2 -

n +

7)

13. x

2 +

3x +

x +

3

14. b

2 -

2b

+ 3

b -

6

(

x +

1)(

x +

3)

(b

+ 3

)(b

- 2

)

15. 2

j 2 +

2j +

3j +

3

16. 2a

2 -

4a

+ a

- 2

(

2j +

3)(

j +

1)

(2a

+ 1

)(a -

2)

17. 6

t2 -

4t -

3t +

2

18. 9x

2 -

3xy +

6x -

2y

(

2t -

1)(

3t -

2)

(3x +

2)(

3x -

y)

So

lve e

ach

eq

ua

tio

n.

Ch

eck

yo

ur s

olu

tio

ns.

19. x(x

- 8

) =

0 {0

, 8}

20. b(b

+ 1

2) =

0 {-

12,

0}

21. (m

- 3

)(m

+ 5

) =

0 {-

5,

3}

22. (a

- 9

)(2

a +

1) =

0 {- 1

2 ,

9}

23. x

2 -

5x =

0 {0

, 5}

24. y

2 +

3y =

0 {-

3,

0}

25. 3a

2 =

6a

{0

, 2}

26. 2

x2 =

3x {0

, 3

2 }

8-2

Answers (Lesson 8-2)

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Co

pyrig

ht ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f Th

e M

cG

raw

-Hill C

om

pan

ies, In

c.

Chapter 8 A6 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

8

14

Gle

ncoe A

lgeb

ra 1

Practi

ce

Usin

g t

he D

istr

ibu

tive P

rop

ert

y

Fa

cto

r e

ach

po

lyn

om

ial.

1. 64 -

40ab

2. 4d

2 +

16

3. 6r2t

- 3rt

2

8(8

- 5

ab

) 4

(d2 +

4)

3rt

(2r -

t)

4. 15ad

+ 3

0a

2d

2

5. 32a

2 +

24b

2

6. 36xy

2 -

48x

2y

15

ad

(1 +

2ad

) 8

(4a

2 +

3b

2)

12

xy(3

y -

4x)

7. 30x

3y +

35x

2y

2

8. 9a

3d

2 -

6ad

3

9. 75b

2g

3 +

60bg

3

5x

2y(6

x +

7y)

3ad

2(3

a2 -

2d

) 1

5b

g3(5

b +

4)

10. 8p

2r2

- 2

4pr3

+ 1

6pr

11. 5x

3y

2 +

10x

2y +

25x

12. 9ax

3 +

18bx

2 +

24cx

8p

r(p

r -

3r2

+ 2

) 5

x(x

2y

2 +

2xy +

5)

3x(3

ax

2 +

6b

x +

8c)

13. x

2 +

4x +

2x +

8

14. 2a

2 +

3a

+ 6a

+ 9

15. 4b

2 -

12b +

2b

- 6

(x +

2)(

x +

4)

(a +

3)(

2a +

3)

(4b

+ 2

)(b

- 3

)

16. 6xy -

8x +

15y -

20

17.

-6mp

+ 4m

+ 1

8p

- 1

2

18. 12a

2 -

15ab

- 1

6a

+ 2

0b

(2x +

5)(

3y -

4)

(-

2m

+ 6

)(3

p -

2)

(3a

- 4

)(4a

- 5

b)

So

lve e

ach

eq

ua

tio

n.

Ch

eck

yo

ur s

olu

tio

ns.

19. x(x

- 3

2)

= 0

20. 4b

(b +

4)

= 0

21. (y

- 3

)(y +

2)

= 0

{

0,

32}

{-

4,

0}

{-

2,

3}

22. (a

+ 6

)(3a

- 7

) =

0

23. (2y +

5)(y -

4)

= 0

24. (4y +

8)(

3y -

4)

= 0

{-

6,

7

3 }

{- 5

2 ,

4}

{-2,

4

3 }

25. 2z2

+ 2

0z

= 0

26. 8p

2 -

4p

= 0

27. 9x

2 =

27x

{-

10,

0}

{ 0,

1

2 }

{0,

3}

28. 18x

2 =

15x

29. 14x

2 =

-21x

30. 8x

2 =

-26x

{0

, 5

6 }

{- 3

2 ,

0}

{- 1

3

4 ,

0}

31. LA

ND

SC

APIN

G A

lan

dsc

ap

ing c

om

pan

y h

as

been

com

mis

sion

ed

to d

esi

gn

a t

rian

gu

lar

flow

er

bed

for

a m

all

en

tran

ce.

Th

e f

inal

dim

en

sion

s of

the f

low

er

bed

have n

ot

been

d

ete

rmin

ed

, bu

t th

e c

om

pan

y k

now

s th

at

the h

eig

ht

wil

l be t

wo f

eet

less

th

an

th

e b

ase

.

Th

e a

rea o

f th

e f

low

er

bed

can

be r

ep

rese

nte

d b

y t

he e

qu

ati

on

A =

1

2 b

2 -

b.

a.

Wri

te t

his

equ

ati

on

in

fact

ore

d f

orm

. A

= b

( 1 −

2 b

- 1)

b.

Su

pp

ose

th

e b

ase

of

the f

low

er

bed

is

16 f

eet.

Wh

at

wil

l be i

ts a

rea?

112 f

t2

32. PH

YSIC

AL S

CIE

NC

E M

r. A

lim

’s s

cien

ce c

lass

lau

nch

ed

a t

oy r

ock

et

from

gro

un

d l

evel

wit

h a

n i

nit

ial

up

ward

velo

city

of

60 f

eet

per

seco

nd

. T

he h

eig

ht h

of

the r

ock

et

in f

eet

above t

he g

rou

nd

aft

er t

seco

nd

s is

mod

ele

d b

y t

he e

qu

ati

on

h =

60t

- 1

6t2

. H

ow

lon

g

was

the r

ock

et

in t

he a

ir b

efo

re i

t re

turn

ed

to t

he g

rou

nd

? 3.7

5 s

8-2

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Lesson 8-2

Ch

ap

ter

8

15

Gle

ncoe A

lgeb

ra 1

Wo

rd

Pro

ble

m P

racti

ce

Usin

g t

he D

istr

ibu

tive P

rop

ert

y

1. PH

YSIC

S A

ccord

ing t

o l

egen

d,

Gali

leo

dro

pp

ed

obje

cts

of

dif

fere

nt

weig

hts

fro

m

the s

o-c

all

ed

“le

an

ing t

ow

er”

of

Pis

a

wh

ile d

evelo

pin

g h

is f

orm

ula

for

free

fall

ing o

bje

cts.

Th

e r

ela

tion

ship

th

at

he

dis

covere

d w

as

that

the d

ista

nce

d a

n

obje

ct f

all

s aft

er t

seco

nd

s is

giv

en

by

d=

16t2

(ig

nori

ng a

ir r

esi

stan

ce).

Th

is

rela

tion

ship

can

be f

ou

nd

in

th

e e

qu

ati

on

h

= 4t

- 1

6t2

, w

here

h i

s th

e h

eig

ht

of

an

obje

ct t

hro

wn

up

ward

fro

m g

rou

nd

level

at

a r

ate

of

32 f

eet

per

seco

nd

. S

olv

e t

he

equ

ati

on

for h

= 0

. t =

0.2

5 a

nd

0

2. SW

IMM

ING

PO

OL T

he a

rea A

of

a

rect

an

gu

lar

swim

min

g p

ool

is g

iven

by

the e

qu

ati

on

A=

12w

-w

2,

wh

ere

w i

s th

e w

idth

of

on

e s

ide.

Wri

te a

n

exp

ress

ion

for

the o

ther

sid

e o

f th

e

pool.

12 -

w

3. C

ON

STR

UC

TIO

N U

niq

ue B

uil

din

g

Com

pan

y i

s co

nst

ruct

ing a

tri

an

gu

lar

roof

tru

ss f

or

a b

uil

din

g.

Th

e w

ork

ers

ass

em

ble

th

e t

russ

wit

h t

he d

imen

sion

s sh

ow

n o

n t

he d

iagra

m b

elo

w.

Usi

ng t

he

Pyth

agore

an

Th

eore

m,

fin

d t

he l

en

gth

of

the s

ides

of

the t

russ

. 3 y

d,

4 y

d,

5 y

d

4. V

ER

TIC

AL J

UM

P Y

ou

r vert

ical

jum

p

heig

ht

is m

easu

red

by s

ubtr

act

ing

you

r st

an

din

g r

each

heig

ht

from

th

e

heig

ht

of

the h

igh

est

poin

t you

can

reach

by j

um

pin

g w

ith

ou

t ta

kin

g a

ru

nn

ing

start

. T

yp

icall

y,

NB

A p

layers

have

vert

ical

jum

p h

eig

hts

of

up

to 3

4 i

nch

es.

If

an

NB

A p

layer

jum

ps

this

hig

h,

his

h

eig

ht h

in

in

ches

above h

is s

tan

din

g

reach

heig

ht

aft

er t

seco

nd

s ca

n b

e

mod

ele

d b

y t

he e

qu

ati

on

h

= 1

62t

- 1

92t2

. S

olv

e t

he e

qu

ati

on

for

h=

0 a

nd

in

terp

ret

the s

olu

tion

. R

ou

nd

you

r an

swer

to t

he n

eare

st h

un

dre

dth

.

t=

0 a

nd

t≈

0.8

44;

Th

e p

layer

lan

ds a

fter

ab

ou

t 0.8

4 s

eco

nd

s.

5. PETS

C

on

ner

toss

es

a d

og t

reat

up

ward

w

ith

an

in

itia

l velo

city

of

13.7

mete

rs p

er

seco

nd

. T

he h

eig

ht

of

the t

reat

above t

he

dog’s

mou

th h

in

mete

rs a

fter t

seco

nd

s is

giv

en

by t

he e

qu

ati

on

.h

= 1

3.7t

- 4

.9t2

a

. A

ssu

min

g t

he d

og d

oesn

’t j

um

p,

aft

er

how

man

y s

eco

nd

s d

oes

the d

og c

atc

h

the t

reat?

2.7

95

b. T

he d

og t

reat

reach

es

its

maxim

um

h

eig

ht

half

way b

etw

een

wh

en

it

was

thro

wn

an

d w

hen

it

was

cau

gh

t. W

hat

is i

ts m

axim

um

heig

ht?

9.6

m

c. H

ow

fast

wou

ld C

on

nor

have t

o t

hro

w

the d

og t

reat

in o

rder

to m

ak

e i

t fl

y

thro

ugh

th

e a

ir f

or

6 s

eco

nd

s?

at

29.4

m/s

2x -

1 y

d

x +

1 y

d

x y

d

8-2

Answers (Lesson 8-2)

Page 7: Answers (Anticipation Guide and Lesson 8-1) © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers Chapter 8 A3 Glencoe Algebra 1 Copyright © Glencoe/McGraw-Hill,

Answers

Co

pyri

gh

t ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f T

he M

cG

raw

-Hill C

om

pan

ies,

Inc.

Chapter 8 A7 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

8

16

Gle

ncoe A

lgeb

ra 1

Lin

ear

Co

mb

inati

on

sT

he g

reate

st c

om

mon

fact

or,

GC

F,

of

two n

um

bers

can

be w

ritt

en

as

a l

inear

com

bin

ati

on

of

the t

wo n

um

bers

. A

lin

ear

com

bin

ati

on

is

an

exp

ress

ion

of

the f

orm

Ax +

By.

W

rit

e t

he g

rea

test

co

mm

on

fa

cto

r o

f 52 a

nd

36 a

s a

lin

ea

r

co

mb

ina

tio

n.

Fir

st,

use

th

e E

ucl

idean

Alg

ori

thm

to f

ind

th

e g

reate

st c

om

mon

fact

or

of

the t

wo n

um

bers

.

1

36 """""

""""""""

52

D

ivid

e t

he g

reate

r num

ber

by t

he lesser

num

ber.

36

2

16 """"

"""""""""

36

ori

gin

al

div

isor;

T

hen d

ivid

e u

sin

g t

he r

em

ain

der

as t

he n

ew

div

isor.

32

4

4 """"

"""""""""

16

se

con

d d

ivis

or;

D

ivid

e a

gain

.

16

0

Sto

p d

ivid

ing.

Last

div

isor

use

d i

s th

e G

CF

. In

th

is c

ase

, 4 i

s th

e G

CF

for

36 a

nd

52.

To w

rite

4 a

s a l

inear

com

bin

ati

on

of

36 a

nd

52,

it n

eed

s to

be w

ritt

en

as:

4 =

36

x +

52y,

wh

ere

x a

nd

y a

re s

om

e i

nte

gers

.

Use

tri

al

an

d e

rror

to d

ete

rmin

e t

he t

wo i

nte

gers

.

Th

e t

wo i

nte

gers

th

at

work

are

x =

3 a

nd

y =

-2.

So,

the l

inear

com

bin

ati

on

for

the g

reate

st

com

mon

fact

or

of

52 a

nd

36 i

s:

4 =

36(3

) +

52(-

2)

Exerc

ises

Writ

e t

he g

rea

test

co

mm

on

fa

cto

r f

or e

ach

pa

ir o

f n

um

bers a

s a

lin

ea

r

co

mb

ina

tio

n.

1. 16,

64

2. 21,

28

16 =

16(1

) +

64(0

)

7 =

21(-

1) +

28(1

)

3. 3,

18

4. 15,

36

3 =

3(1

) +

18(0

) 3

= 1

5(5

) -

36(2

)

5. 6,

8

6. 18,

42

2 =

6(-

1) +

8(1

)

6 =

18(-

2) +

42(1

)

En

rich

men

t8-2 Exam

ple

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Lesson 8-3

Ch

ap

ter

8

17

Gle

ncoe A

lgeb

ra 1

Stu

dy

Gu

ide a

nd

In

terv

en

tio

n

Qu

ad

rati

c E

qu

ati

on

s:

x2 +

bx +

c =

0

Facto

r x

2 +

bx +

c

To f

act

or

a t

rin

om

ial

of

the f

orm

x2 +

bx +

c,

fin

d t

wo i

nte

gers

, m

an

d p

, w

hose

su

m i

s equ

al

to b

an

d w

hose

pro

du

ct i

s equ

al

to c

.

F

acto

r e

ach

po

lyn

om

ial.

a. x

2 +

7x

+ 1

0

In

th

is t

rin

om

ial,

b =

7 a

nd

c =

10.

Facto

rs o

f 10

Su

m o

f F

acto

rs

1,

10

11

2,

57

S

ince

2 +

5 =

7 a

nd

2 #

5 =

10,

let

m =

2

an

d p

= 5

.

x

2 +

7x +

10 =

(x +

5)(

x +

2)

b. x

2 -

8x

+ 7

In t

his

tri

nom

ial,

b =

-8 a

nd

c =

7.

Noti

ce t

hat

m +

p i

s n

egati

ve a

nd

mp

is

posi

tive,

so m

an

d p

are

both

negati

ve.

Sin

ce -

7 +

(-

1)

= -

8 a

nd

(-

7)(

-1)

= 7

, m

= -

7 a

nd

p =

-1.

x2 -

8x +

7 =

(x -

7)(

x -

1)

F

acto

r x

2 +

6x

- 1

6.

In t

his

tri

nom

ial,

b =

6 a

nd

c =

-16.

Th

is

mean

s m

+ p

is

posi

tive a

nd

mp

is

negati

ve.

Mak

e a

lis

t of

the f

act

ors

of

-16,

wh

ere

on

e

fact

or

of

each

pair

is

posi

tive.

Facto

rs o

f -

16

Su

m o

f F

acto

rs

1, -

16

-15

-1,

16

15

2, -

8-

6

-2,

86

Th

ere

fore

, m

= -

2 a

nd

p =

8.

x2 +

6x -

16 =

(x -

2)(

x +

8)

Exerc

ises

Fa

cto

r e

ach

po

lyn

om

ial.

1. x

2 +

4x +

3

2. m

2 +

12m

+ 3

2

3. r2

- 3

r +

2

(

x +

3)(

x +

1)

(m

+ 4

)(m

+ 8

) (

r -

2)(

r -

1)

4. x

2 -

x -

6

5. x

2 -

4x -

21

6. x

2 -

22

x +

121

(

x -

3)(

x +

2)

(x -

7)(

x +

3)

(x -

11)(

x -

11)

7. t2

- 4

t -

12

8. p

2 -

16p

+ 6

4

9. 9 -

10

x +

x2

(

t +

2)(

t -

6)

(p

- 8

)(p

- 8

) (

9 -

x)(

1 -

x)

10. x

2 +

6x +

5

11. a

2 +

8a

- 9

12. y

2 -

7y -

8

(

x +

5)(

x +

1)

(a

- 1

)(a +

9)

(y -

8)(

y +

1)

13. x

2 -

2x -

3

14. y

2 +

14

y +

13

15. m

2 +

9m

+ 2

0

(

x -

3)(

x +

1)

(y +

1)(

y +

13)

(m

+ 4

)(m

+ 5

)

16. x

2 +

12

x +

20

17. a

2 -

14a

+ 2

4

18. 18 +

11

y +

y2

(

x +

10)(

x +

2)

(a

- 2

)(a -

12)

(9 +

y)(

2 +

y)

19. x

2 +

2xy +

y2

20. a

2 -

4a

b +

4b

2

21. x

2 +

6xy -

7y

2

(

x +

y)(

x +

y)

(a

- 2

b)(

a -

2b

) (

x +

7y)(

x -

y)

8-3

Exam

ple

1Exam

ple

2

Facto

rin

g x

2 +

bx +

cx

2 +

bx +

c =

(x +

m)(

x +

p),

where

m +

p =

b a

nd m

p =

c.

Answers (Lesson 8-2 and Lesson 8-3)

Page 8: Answers (Anticipation Guide and Lesson 8-1) © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers Chapter 8 A3 Glencoe Algebra 1 Copyright © Glencoe/McGraw-Hill,

Co

pyrig

ht ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f Th

e M

cG

raw

-Hill C

om

pan

ies, In

c.

Chapter 8 A8 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

8

18

Gle

ncoe A

lgeb

ra 1

Stu

dy

Gu

ide a

nd

In

terv

en

tio

n

(con

tin

ued

)

Qu

ad

rati

c E

qu

ati

on

s:

x2 +

bx +

c =

0

So

lve E

qu

ati

on

s b

y F

act

ori

ng

F

act

ori

ng a

nd

th

e Z

ero

Pro

du

ct P

rop

ert

y c

an

be u

sed

to

solv

e m

an

y e

qu

ati

on

s of

the f

orm

x2 +

bx +

c =

0.

S

olv

e x

2 +

6x

= 7

. C

heck

yo

ur s

olu

tio

ns.

x

2 +

6x =

7

Origin

al equation

x

2 +

6x -

7 =

0

Rew

rite

equation s

o t

hat

one s

ide e

quals

0.

(x

- 1

)(x +

7) =

0

Facto

r.

x -

1 =

0 or

x +

7 =

0

Zero

Pro

duct

Pro

pert

y

x =

1

x =

-7

Solv

e e

ach e

quation.

Th

e s

olu

tion

set

is {

1, -

7}.

Sin

ce 1

2 +

6 =

7 a

nd

(-

7)2

+ 6

(-7) =

7,

the s

olu

tion

s ch

eck

.

R

OC

KET L

AU

NC

H A

ro

ck

et

is f

ired

wit

h a

n i

nit

ial

velo

cit

y o

f 2288

feet

per s

eco

nd

. H

ow

ma

ny

seco

nd

s w

ill

it t

ak

e f

or t

he r

ock

et

to h

it t

he g

ro

un

d?

Th

e f

orm

ula

h =

vt -

16t2

giv

es

the h

eig

ht

h o

f th

e r

ock

et

aft

er

t se

con

ds

wh

en

th

e i

nit

ial

velo

city

v i

s giv

en

in

feet

per

seco

nd

.

h

= v

t -

16t2

F

orm

ula

0 =

2288

t -

16

t2

Substitu

te.

0 =

16

t(143 -

t)

Facto

r.

16t =

0 or

143 -

t =

0

Zero

Pro

duct

Pro

pert

y

t =

0

t =

143

Solv

e e

ach e

quation.

Th

e v

alu

e t

= 0

rep

rese

nts

th

e t

ime a

t la

un

ch.

Th

e r

ock

et

retu

rns

to t

he g

rou

nd

in

143

seco

nd

s, o

r a l

ittl

e l

ess

th

an

2.5

min

ute

s aft

er

lau

nch

.

Exerc

ises

So

lve e

ach

eq

ua

tio

n.

Ch

eck

th

e s

olu

tio

ns.

1. x

2 -

4x +

3 =

0 {1

, 3}

2. y

2 -

5y +

4 =

0 {1

, 4}

3. m

2 +

10m

+ 9

= 0

4. x

2 =

x +

2 {-

1,

2}

5. x

2 -

4x =

5 {-

1,

5}

6. x

2 -

12

x +

36 =

0 {6}

7. t2

- 8

= -

7t {-

8, 1}

8. p

2 =

9p -

14 {2

, 7}

9. -

9 -

8x +

x2 =

0 {-

1, 9}

10. x

2 +

6 =

5x {2,

3}

11. a

2 =

11a

- 1

8 {2,

9}

12. y

2 -

8y +

15

= 0

{3,

5}

13. x

2 =

24 -

10

x {-

12,

2}

14. a

2 -

18a

= -

72 {6,

12}

15. b

2 =

10b

- 1

6 {2,

8}

Use t

he f

orm

ula

h =

vt -

16t

2 t

o s

olv

e e

ach

pro

ble

m.

16. FO

OTB

ALL A

pu

nte

r ca

n k

ick

a f

ootb

all

wit

h a

n i

nit

ial

velo

city

of

48 f

eet

per

seco

nd

. H

ow

man

y s

eco

nd

s w

ill

it t

ak

e f

or

the b

all

to r

etu

rn t

o t

he g

rou

nd

? 3 s

eco

nd

s

17. B

ASEB

ALL A

ball

is

thro

wn

up

wit

h a

n i

nit

ial

velo

city

of

32 f

eet

per

seco

nd

. H

ow

man

y

seco

nd

s w

ill

it t

ak

e f

or

the b

all

to r

etu

rn t

o t

he g

rou

nd

? 2 s

eco

nd

s

18. R

OC

KET L

AU

NC

H If

a r

ock

et

is l

au

nch

ed

wit

h a

n i

nit

ial

velo

city

of

1600 f

eet

per

seco

nd

, w

hen

wil

l th

e r

ock

et

be 1

4,4

00 f

eet

hig

h?

at

10 s

eco

nd

s a

nd

at

90 s

eco

nd

s

8-3

Exam

ple

1

Exam

ple

2

{-1, -

9}

Lesson 8-3

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Sk

ills

Pra

ctic

e

Qu

ad

rati

c E

qu

ati

on

s:

x2 +

bx +

c =

0

Fa

cto

r e

ach

po

lyn

om

ial.

1. t2

+ 8

t +

12

2. n

2 +

7n

+ 1

2

(

t +

2)(

t +

6)

(n

+ 3

)(n

+ 4

)

3. p

2 +

9p

+ 2

0

4. h

2 +

9h

+ 1

8

(

p +

5)(

p +

4)

(h

+ 6

)(h

+ 3

)

5. n

2 +

3n

- 1

8

6. x

2 +

2x -

8

(

n +

6)(

n -

3)

(x +

4)(

x -

2)

7. y

2 -

5y -

6

8. g

2 +

3g -

10

(

y +

1)(

y -

6)

(g

+ 5

)(g

- 2

)

9. r2

+ 4

r -

12

10. x

2 -

x -

12

(

r -

2)(

r +

6)

(x -

4)(

x +

3)

11. w

2 -

w -

6

12. y

2 -

6y +

8

(

w -

3)(

w +

2)

(y -

2)(

y -

4)

13. x

2 -

8x +

15

14. b

2 -

9b

+ 8

(

x -

5)(

x -

3)

(b

- 1

)(b

- 8

)

15. t2

- 1

5t +

56

16. -

4 -

3m

+ m

2

(

t -

7)(

t -

8)

(m

- 4

)(m

+ 1

)

So

lve e

ach

eq

ua

tio

n.

Ch

eck

th

e s

olu

tio

ns.

17. x

2 -

6x +

8 =

0 {2,

4}

18. b

2 -

7b

+ 1

2 =

0 {3,

4}

19. m

2 +

5m

+ 6

= 0

{-

3, -

2}

20. d

2 +

7d

+ 1

0 =

0 {-

5, -

2}

21. y

2 -

2y -

24

= 0

{-

4,

6}

22. p

2 -

3p

= 1

8 {-

3,

6}

23. h

2 +

2h

= 3

5 {-

7,

5}

24. a

2 +

14a

= -

45 {-

9, -

5}

25. n

2 -

36 =

5n

{-

4,

9}

26. w

2 +

30

= 1

1w

{5,

6}

8-3

Ch

ap

ter

8

19

Gle

ncoe A

lgeb

ra 1

Answers (Lesson 8-3)

Page 9: Answers (Anticipation Guide and Lesson 8-1) © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers Chapter 8 A3 Glencoe Algebra 1 Copyright © Glencoe/McGraw-Hill,

Answers

Co

pyri

gh

t ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f T

he M

cG

raw

-Hill C

om

pan

ies,

Inc.

Chapter 8 A9 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

8

20

Gle

ncoe A

lgeb

ra 1

Practi

ce

Qu

ad

rati

c E

qu

ati

on

s:

x2 +

bx +

c =

0

Fa

cto

r e

ach

po

lyn

om

ial.

1. a

2 +

10a

+ 2

4

2. h

2 +

12h

+ 2

7

3. x

2 +

14

x +

33

(a +

4)(

a +

6)

(h

+ 3

)(h

+ 9

) (

x +

11)(

x +

3)

4. g

2 -

2g -

63

5. w

2 +

w -

56

6. y

2 +

4y -

60

(g +

7)(

g -

9)

(w

+ 8

)(w

- 7

) (

y +

10)(

y -

6)

7. b

2 +

4b

- 3

2

8. n

2 -

3n

- 2

8

9. t2

+ 4

t -

45

(b -

4)(

b +

8)

(n

- 7

)(n

+ 4

) (

t -

5)(

t +

9)

10. z2

- 1

1z +

30

11. d

2 -

16d

+ 6

3

12. x

2 -

11

x +

24

(z -

6)(

z -

5)

(d

- 9

)(d

- 7

) (

x -

3)(

x -

8)

13. q

2 -

q -

56

14. x

2 -

6x -

55

15. 32 +

18r +

r2

(q -

8)(

q +

7)

(x +

5)(

x -

11)

(r +

16)(

r +

2)

16. 48 -

16g +

g2

17. j 2

- 9

jk -

10

k2

18. m

2 -

mv -

56v

2

(g -

12)(

g -

4)

( j -

10

k)(

j +

k)

(m

- 8

v)(

m +

7v)

So

lve e

ach

eq

ua

tio

n.

Ch

eck

th

e s

olu

tio

ns.

19. x

2 +

17x +

42

= 0

20. p

2 +

5p

- 8

4 =

0

21. k

2 +

3k -

54 =

0{-

14, -

3}

{-

12,

7}

{-

9,

6}

22. b

2 -

12

b -

64 =

0

23. n

2 +

4n

= 3

2

24. h

2 -

17h

= -

60

{-

4,

16}

{-

8,

4}

{5,

12}

25. t2

- 2

6t =

56

26. z2

- 1

4z =

72

27. y

2 -

84

= 5

y

{-

2,

28}

{-

4,

18}

{-

7,

12}

28. 80 +

a2 =

18a

29. u

2 =

16u

+ 3

6

30. 17

r +

r2 =

-52

{8,

10}

{-

2,

18}

{-

13, -

4}

31. F

ind

all

valu

es

of

k s

o t

hat

the t

rin

om

ial

x2 +

kx -

35 c

an

be f

act

ore

d u

sin

g i

nte

gers

. -

34, -

2,

2,

34

32. C

ON

STR

UC

TIO

N A

con

stru

ctio

n c

om

pan

y i

s p

lan

nin

g t

o p

ou

r co

ncr

ete

for

a d

rivew

ay.

Th

e l

en

gth

of

the d

rivew

ay i

s 16 f

eet

lon

ger

than

its

wid

th w

.

a.

Wri

te a

n e

xp

ress

ion

for

the a

rea o

f th

e d

rivew

ay.

w(w

+ 1

6)

ft 2

b.

Fin

d t

he d

imen

sion

s of

the d

rivew

ay i

f it

has

an

are

a o

f 260 s

qu

are

feet.

10 f

t b

y 2

6 f

t

32. W

EB

DESIG

N Jan

eel

has

a 1

0-i

nch

by 1

2-i

nch

ph

oto

gra

ph

. S

he w

an

ts t

o s

can

th

e

ph

oto

gra

ph

, th

en

red

uce

th

e r

esu

lt b

y t

he s

am

e a

mou

nt

in e

ach

dim

en

sion

to p

ost

on

her

Web s

ite.

Jan

eel

wan

ts t

he a

rea o

f th

e i

mage t

o b

e o

ne e

igh

th t

hat

of

the o

rigin

al

ph

oto

gra

ph

.

a.

Wri

te a

n e

qu

ati

on

to r

ep

rese

nt

the a

rea o

f th

e r

ed

uce

d i

mage.

(10 -

x)(

12 -

x) =

15,

or

x2 -

22x +

105 =

0

b.

Fin

d t

he d

imen

sion

s of

the r

ed

uce

d i

mage.

3 i

n.

by 5

in

.

8-3

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Lesson 8-3

Ch

ap

ter

8

21

Gle

ncoe A

lgeb

ra 1

1. C

OM

PA

CT D

ISC

S A

sta

nd

ard

jew

el

case

fo

r a c

om

pact

dis

c h

as

a w

idth

2 c

m

gre

ate

r th

an

its

len

gth

. T

he a

rea f

or

the

fron

t co

ver

is 1

68 s

qu

are

cen

tim

ete

rs.

Th

e f

irst

tw

o s

tep

s to

fin

din

g t

he v

alu

e o

f x a

re s

how

n b

elo

w.

Solv

e t

he e

qu

ati

on

an

d f

ind

th

e l

en

gth

of

the c

ase

.

Len

gth

×w

idth = a

rea

x(x + 2

) = 1

68

x2 + 2

x - 1

68 = 0

-14 o

r 12;

12 c

m

2. M

ATH

GA

MES

F

ion

a a

nd

Gre

g p

lay a

n

um

ber

gu

ess

ing g

am

e.

Gre

g g

ives

Fio

na

this

hin

t abou

t h

is t

wo s

ecr

et

nu

mbers

, “T

he p

rod

uct

of

the t

wo c

on

secu

tive

posi

tive i

nte

gers

th

at

I am

th

ink

ing o

f is

11 m

ore

th

an

th

eir

su

m.”

Wh

at

are

G

reg’s

nu

mbers

? 4 a

nd

5

3. B

RID

GE E

NG

INEER

ING

A

car

dri

vin

g

over

a s

usp

en

sion

bri

dge i

s su

pp

ort

ed

by

a c

able

han

gin

g b

etw

een

th

e e

nd

s of

the

bri

dge.

Sin

ce i

ts s

hap

e i

s p

ara

boli

c, i

t ca

n

be m

od

ele

d b

y a

qu

ad

rati

c equ

ati

on

. T

he

heig

ht

above t

he r

oad

bed

of

a b

rid

ge’s

ca

ble

h (

in i

nch

es)

measu

red

at

dis

tan

ce

d (

in y

ard

s) f

rom

th

e f

irst

tow

er

is g

iven

by t

he e

qu

ati

on

h=

d2-

36d+

324.

If t

he d

river

of

a c

ar

look

s ou

t at

a h

eig

ht

of

49 i

nch

es

above t

he r

oad

bed

, at

wh

at

dis

tan

ce(s

) fr

om

th

e t

ow

er

wil

l th

e

dri

ver’

s eyes

be a

t th

e s

am

e h

eig

ht

as

the

cable

? at

11 a

nd

25 y

ds f

rom

th

e

firs

t to

wer

4. PH

YSIC

AL S

CIE

NC

E T

he b

oil

ing p

oin

t of

wate

r d

ep

en

ds

on

alt

itu

de.

Th

e f

oll

ow

ing

equ

ati

on

ap

pro

xim

ate

s th

e n

um

ber

of

degre

es

D b

elo

w 2

12ºF

at

wh

ich

wate

r w

ill

boil

at

alt

itu

de h

.

D2+

520

D=

H

In D

en

ver,

Colo

rad

o,

the a

ltit

ud

e i

s ap

pro

xim

ate

ly 5

300 f

eet

above s

ea l

evel.

A

t ap

pro

xim

ate

ly w

hat

tem

pera

ture

does

wate

r boil

in

Den

ver?

D=

10°

dro

p T

he b

oilin

g p

oin

t is

ab

ou

t 202°F

.

5. M

ON

UM

EN

TS

Su

san

is

desi

gn

ing a

p

yra

mid

al

ston

e m

on

um

en

t fo

r a l

oca

l p

ark

. T

he d

esi

gn

sp

eci

fica

tion

s te

ll h

er

that

the h

eig

ht

need

s to

be 9

feet,

th

e

wid

th o

f th

e b

ase

mu

st b

e 5

feet

less

th

an

th

e l

en

gth

, an

d t

he v

olu

me s

hou

ld

be 1

50 c

ubic

feet.

Reca

ll t

hat

the

volu

me o

f a p

yra

mid

is

giv

en

by V

= 1 − 3

Bh

,

wh

ere

B i

s th

e a

rea o

f th

e b

ase

an

d h

is

the h

eig

ht.

a.

Wri

te a

nd

solv

e a

n e

qu

ati

on

to f

ind

th

e

wid

th o

f th

e b

ase

of

the m

on

um

en

t.

150 =

1 − 3w

(w+

5) ·

9 o

r

3w

2+

15

w-

150 =

0;

w=

{5, -

10}

b.

Inte

rpre

t each

an

swer

in t

erm

s of

the

situ

ati

on

. w=

5:

the w

idth

of

the

pyra

mid

is 5

feet;

w=-

10:

neg

ati

ve l

en

gth

do

esn

’t m

ake

sen

se i

n t

he s

itu

ati

on

.

Wo

rd

Pro

ble

m P

racti

ce

Qu

ad

rati

c E

qu

ati

on

s:

x2 +

bx +

c =

0

d

h

8-3

Answers (Lesson 8-3)

Page 10: Answers (Anticipation Guide and Lesson 8-1) © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers Chapter 8 A3 Glencoe Algebra 1 Copyright © Glencoe/McGraw-Hill,

Co

pyrig

ht ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f Th

e M

cG

raw

-Hill C

om

pan

ies, In

c.

Chapter 8 A10 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

8

22

Gle

ncoe A

lgeb

ra 1

En

rich

men

t

Pu

zzlin

g P

rim

es

A p

rim

e n

um

ber

has

on

ly t

wo f

act

ors

, it

self

an

d 1

. T

he n

um

ber

6 i

s n

ot

pri

me b

eca

use

it

has

2 a

nd

3 a

s fa

ctors

; 5 a

nd

7 a

re p

rim

e.

Th

e n

um

ber

1 i

s n

ot

con

sid

ere

d t

o b

e p

rim

e.

1. U

se a

calc

ula

tor

to h

elp

you

fin

d t

he 2

5 p

rim

e n

um

bers

less

th

an

100.

2

, 3,

5,

7,

11,

13,

17,

19,

23,

29,

31,

37 4

1,

43,

47,

53,

59,

61,

67,

71,

73,

79,

83,

89,

97

Pri

me n

um

bers

have i

nte

rest

ed

math

em

ati

cian

s fo

r ce

ntu

ries.

Th

ey h

ave t

ried

to f

ind

exp

ress

ion

s th

at

wil

l giv

e a

ll t

he p

rim

e n

um

bers

, or

on

ly p

rim

e n

um

bers

. In

th

e 1

700s,

E

ule

r d

isco

vere

d t

hat

the t

rin

om

ial

x2 +

x +

41 w

ill

yie

ld p

rim

e n

um

bers

for

valu

es

of

x

from

0 t

hro

ugh

39.

2. F

ind

th

e p

rim

e n

um

bers

gen

era

ted

by E

ule

r’s

form

ula

for

x f

rom

0 t

hro

ugh

7.

4

1,

43,

47,

53,

61,

71,

83,

97

3. S

how

th

at

the t

rin

om

ial

x2 +

x +

31 w

ill

not

giv

e p

rim

e n

um

bers

for

very

man

y v

alu

es

of

x.

I

t w

ork

s f

or

x =

0,

2,

3,

5,

an

d 6

bu

t n

ot

for

x =

1,

4,

an

d 7

.

4. F

ind

th

e l

arg

est

pri

me n

um

ber

gen

era

ted

by E

ule

r’s

form

ula

.

1601

Gold

ba

ch’s

Con

ject

ure

is

that

every

non

zero

even

nu

mber

gre

ate

r th

an

2 c

an

be w

ritt

en

as

the s

um

of

two p

rim

es.

No o

ne h

as

ever

pro

ved

th

at

this

is

alw

ays

tru

e,

bu

t n

o o

ne h

as

fou

nd

a c

ou

nte

rexam

ple

, eit

her.

5. S

how

th

at

Gold

bach

’s C

on

ject

ure

is

tru

e f

or

the f

irst

5 e

ven

nu

mbers

gre

ate

r th

an

2.

4

= 2

+ 2

, 6 =

3 +

3,

8 =

3 +

5,

10

= 3

+ 7

, 12 =

5 +

7

6. G

ive a

way t

hat

som

eon

e c

ou

ld d

isp

rove G

old

bach

’s C

on

ject

ure

.

F

ind

an

even

nu

mb

er

that

can

no

t b

e w

ritt

en

as t

he s

um

of

two

pri

mes.

8-3

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Lesson 8-4

Ch

ap

ter

8

23

Gle

ncoe A

lgeb

ra 1

Stu

dy

Gu

ide a

nd

In

terv

en

tio

n

Qu

ad

rati

c E

qu

ati

on

s:

ax

2 +

bx +

c =

0

Facto

r ax

2 +

bx

+ c

T

o f

act

or

a t

rin

om

ial

of

the f

orm

ax

2 +

bx +

c,

fin

d t

wo i

nte

gers

, m

an

d p

wh

ose

pro

du

ct i

s equ

al

to a

c an

d w

hose

su

m i

s equ

al

to b

. If

th

ere

are

no i

nte

gers

th

at

sati

sfy t

hese

requ

irem

en

ts,

the p

oly

nom

ial

is c

all

ed

a p

rim

e p

oly

no

mia

l.

F

acto

r 2x

2 +

15x +

18.

In t

his

exam

ple

, a

= 2

, b

= 1

5,

an

d c

= 1

8.

You

need

to f

ind

tw

o n

um

bers

th

at

have a

su

m o

f 15 a

nd

a p

rod

uct

of

2

18 o

r 36.

Mak

e a

lis

t of

the f

act

ors

of

36 a

nd

look

for

the p

air

of

fact

ors

wit

h a

su

m o

f 15.

Facto

rs o

f 36

Su

m o

f F

acto

rs

1,

36

37

2,

18

20

3,

12

15

U

se t

he p

att

ern

ax

2 +

mx +

px +

c,

wit

h

a

= 2

, m

= 3

, p

= 1

2,

an

d c

= 1

8.

2

x2 +

15x +

18 =

2x

2 +

3x +

12x +

18

= (

2x

2 +

3x) +

(1

2x +

18)

= x

(2x +

3) +

6(2

x +

3)

= (

x +

6)(

2x +

3)

Th

ere

fore

, 2x

2 +

15x +

18 =

(x +

6)(

2x +

3).

F

acto

r 3x

2 -

3x -

18.

Note

th

at

the G

CF

of

the t

erm

s 3

x2,

3x,

an

d 1

8 i

s 3.

Fir

st f

act

or

ou

t th

is G

CF

.

3x

2 -

3x -

18 =

3(x

2 -

x -

6).

Now

fact

or

x2 -

x -

6.

Sin

ce a

= 1

, fi

nd

th

e

two f

act

ors

of -

6 w

ith

a s

um

of -

1.

Facto

rs o

f -

6S

um

of

Facto

rs

1, -

6-

5

-1,

65

-2,

31

2, -

3-

1

Now

use

th

e p

att

ern

(x +

m)(

x +

p)

wit

h

m =

2 a

nd

p =

-3.

x2 -

x -

6 =

(x +

2)(

x -

3)

Th

e c

om

ple

te f

act

ori

zati

on

is

3x

2 -

3x -

18 =

3(x

+ 2

)(x -

3).

Fa

cto

r e

ach

po

lyn

om

ial,

if

po

ssib

le.

If t

he p

oly

no

mia

l ca

nn

ot

be f

acto

red

usin

g

inte

gers,

writ

e prim

e.

1. 2

x2 -

3x -

2

2. 3

m2 -

8m

- 3

3. 16

r2 -

8r

+ 1

(

2x +

1)(

x -

2)

(3

m +

1)(

m -

3)

(4

r -

1)(

4r -

1)

4. 6

x2 +

5x -

6

5. 3

x2 +

2x -

8

6. 18

x2 -

27

x -

5

(

2x +

3)(

3x -

2)

(3

x -

4)(

x +

2)

(3

x -

5)(

6x +

1)

7. 2

a2 +

5a

+ 3

8. 18

y2 +

9y -

5

9. -

4t2

+ 1

9t -

21

(

2a

+ 3

)(a

+ 1

) (

6y +

5)(

3y -

1)

(4t -

7)(

3 -

t)

10. 8

x2 -

4x -

24

11. 28

p2 +

60p

- 2

5

12. 48x

2 +

22

x -

15

(

4x -

8)(

2x +

3)

(2

p +

5)(

14p

- 5

) (

6x +

5)(

8x -

3)

13. 3y

2 -

6y -

24

14. 4

x2 +

26x -

48

15. 8

m2 -

44

m +

48

3

(y +

2)(

y -

4)

2(x

+ 8

)(2x -

3)

4(2

m -

3)(

m -

4)

16. 6x

2 -

7x +

18

17. 2

a2 -

14

a +

18

18. 18 +

11y +

2y

2

p

rim

e

2(a

2 -

7a +

9)

pri

me

8-4

Exam

ple

1Exam

ple

2

Exerc

ises

Answers (Lesson 8-3 and Lesson 8-4)

Page 11: Answers (Anticipation Guide and Lesson 8-1) © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers Chapter 8 A3 Glencoe Algebra 1 Copyright © Glencoe/McGraw-Hill,

Answers

Co

pyri

gh

t ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f T

he M

cG

raw

-Hill C

om

pan

ies,

Inc.

Chapter 8 A11 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

8

24

Gle

ncoe A

lgeb

ra 1

So

lve E

qu

ati

on

s b

y F

act

ori

ng

F

act

ori

ng a

nd

th

e Z

ero

Pro

du

ct P

rop

ert

y c

an

be u

sed

to

solv

e s

om

e e

qu

ati

on

s of

the f

orm

ax

2 +

bx +

c =

0.

S

olv

e 1

2x

2 +

3x =

2 -

2x

. C

heck

yo

ur s

olu

tio

ns.

12

x2 +

3x =

2 -

2x

Origin

al equation

12x

2 +

5x -

2 =

0

Rew

rite

equation s

o t

hat

one s

ide e

quals

0.

(3

x +

2)(

4x -

1)

= 0

F

acto

r th

e left s

ide.

3

x +

2 =

0 o

r 4

x -

1 =

0

Zero

Pro

duct

Pro

pert

y

x =

- 2

3

x =

1

4

Solv

e e

ach e

quation.

Th

e s

olu

tion

set

is {-

2

3 ,

1

4 } .

Sin

ce 1

2 (-

2

3 ) 2

+ 3

(- 2

3 ) =

2 -

2 (-

2

3 ) a

nd

12 ( 1

4 ) 2

+ 3

( 1

4 ) =

2 -

2 ( 1

4 ) ,

the s

olu

tion

s ch

eck

.

So

lve e

ach

eq

ua

tio

n.

Ch

eck

th

e s

olu

tio

ns.

1. 8x

2 +

2x -

3 =

0

2. 3n

2 -

2n

- 5

= 0

3. 2

d2 -

13

d -

7 =

0

{

1

2 , -

3

4 }

{-

1,

5

3 }

{-

1

2 ,

7}

4. 4

x2 =

x +

3

5. 3x

2 -

13x =

10

6. 6

x2 -

11x -

10 =

0

{

1, -

3

4 }

{-

2

3 ,

5}

{-

2

3 ,

5

2 }

7. 2

k2 -

40 =

-11k

8. 2p

2 =

-21p

- 4

0

9.

-7 -

18x +

9x

2 =

0

{-

8,

5

2 }

{-

5

2 , -

8}

{ 7

3 , -

1

3 }

10. 12x

2 -

15 =

-8

x

11. 7a

2 =

-65a

- 1

8

12. 16

y2 -

2y -

3 =

0

{- 3

2 ,

5

6 }

{-

2

7 , -

9 }

{ 1

2 , -

3

8 }

13. 8

x2 +

5x =

3 +

7x

14. 4a

2 -

18

a +

5 =

15

15. 3

b2 -

18

b =

10b

- 4

9

{ 3

4 , -

1

2 }

{-

1

2 ,

5}

{ 7

3 ,

7}

16. T

he d

iffe

ren

ce o

f th

e s

qu

are

s of

two c

on

secu

tive o

dd

in

tegers

is

24.

Fin

d t

he i

nte

gers

. -

5, -

7 a

nd

5,

7

17. G

EO

METR

Y T

he l

en

gth

of

a C

harl

ott

e,

Nort

h C

aro

lin

a,

con

serv

ato

ry g

ard

en

is

20 y

ard

s gre

ate

r th

an

its

wid

th.

Th

e a

rea i

s 300 s

qu

are

yard

s. W

hat

are

th

e d

imen

sion

s?

30 y

d b

y 1

0 y

d

18. G

EO

METR

Y A

rect

an

gle

wit

h a

n a

rea o

f 24 s

qu

are

in

ches

is

fo

rmed

by c

utt

ing s

trip

s of

equ

al

wid

th f

rom

a r

ect

an

gu

lar

pie

ce

of

pap

er.

Fin

d t

he d

imen

sion

s of

the n

ew

rect

an

gle

if

the o

rigin

al

rect

an

gle

measu

res

8 i

nch

es

by 6

in

ches.

6 i

n.

by 4

in

.

8 in

.

x

6 in

.

x

x x

8-4 Exam

ple

Exerc

ises

Stu

dy

Gu

ide a

nd

In

terv

en

tio

n

(con

tin

ued

)

Qu

ad

rati

c E

qu

ati

on

s:

ax

2 +

bx +

c =

0

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Lesson 8-4

Ch

ap

ter

8

25

Gle

ncoe A

lgeb

ra 1

Sk

ills

Pra

ctic

e

Qu

ad

rati

c E

qu

ati

on

s:

ax

2 +

bx +

c =

0

Fa

cto

r e

ach

po

lyn

om

ial,

if

po

ssib

le.

If t

he p

oly

no

mia

l ca

nn

ot

be f

acto

red

usin

g

inte

gers,

writ

e prim

e.

1. 2

x2 +

5x +

2

2. 3n

2 +

5n

+ 2

(

x +

2)(

2x +

1)

(3

n +

2)(

n +

1)

3. 2

t2 +

9t

- 5

4. 3g

2 -

7g +

2

(

t +

5)(

2t -

1)

(3

g -

1)(

g -

2)

5. 2

t2 -

11t

+ 1

5

6. 2x

2 +

3x -

6

(

t -

3)(

2t -

5)

pri

me

7. 2

y2 +

y -

1

8. 4

h2 +

8h

- 5

(

y +

1)(

2y -

1)

(2

h +

5)(

2h

- 1

)

9. 4

x2 -

3x -

3

10. 4

b2 +

15b

- 4

p

rim

e

(4

b -

1)(

b +

4)

11. 9

p2 +

6p

- 8

12. 6

q2 -

13q

+ 6

(

3p

- 2

)(3p

+ 4

) (

3q

- 2

)(2q

- 3

)

13. 3

a2 +

30a

+ 6

3

14. 10w

2 -

19w

- 1

5

3

(a +

7)(

a +

3)

(2w

- 5

)(5

w +

3)

So

lve e

ach

eq

ua

tio

n.

Ch

eck

th

e s

olu

tio

ns.

15. 2x

2 +

7x +

3 =

0 {-

3, - 1

2 }

16. 3w

2 +

14w

+ 8

= 0

{-

4, -

2

3 }

17. 3

n2 -

7n

+ 2

= 0

{ 1

3 ,

2}

18. 5d

2 -

22

d +

8 =

0 { 2

5 ,

4}

19. 6

h2 +

8h

+ 2

= 0

{-

1, -

1

3 }

20. 8

p2 -

16

p =

10 {-

1

2 ,

5

2 }

21. 9

y2 +

18y -

12 =

6y {-

2,

2

3 }

22. 4

a2 -

16

a =

-15 { 3

2 ,

5

2 }

23. 10

b2 -

15

b =

8b -

12 { 4

5 ,

3

2 }

24. 6

d2 +

21d

= 1

0d

+ 3

5 {-

7

2 ,

5

3 }

8-4

Answers (Lesson 8-4)

Page 12: Answers (Anticipation Guide and Lesson 8-1) © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers Chapter 8 A3 Glencoe Algebra 1 Copyright © Glencoe/McGraw-Hill,

Co

pyrig

ht ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f Th

e M

cG

raw

-Hill C

om

pan

ies, In

c.

Chapter 8 A12 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

8

26

Gle

ncoe A

lgeb

ra 1

Practi

ce

Qu

ad

rati

c E

qu

ati

on

s:

ax

2 +

bx +

c =

0

Fa

cto

r e

ach

po

lyn

om

ial,

if

po

ssib

le.

If t

he p

oly

no

mia

l ca

nn

ot

be f

acto

red

usin

g

inte

gers,

writ

e prim

e.

1. 2b

2 +

10b

+ 1

2

2. 3g

2 +

8g +

4

3. 4x

2 +

4x -

3

2

(b +

2)(

b +

3)

(3

g +

2)(

g +

2)

(2x +

3)(

2x -

1)

4. 8b

2 -

5b -

10

5. 6m

2 +

7m

- 3

6. 10d

2 +

17d

- 2

0

p

rim

e

(3m

- 1

)(2m

+ 3

) (

5d

- 4

)(2

d +

5)

7. 6a

2 -

17a

+ 1

2

8. 8w

2 -

18w

+ 9

9. 10x

2 -

9x +

6

(

3a

- 4

)(2

a -

3)

(4

w -

3)(

2w

- 3

) p

rim

e

10. 15n

2 -

n -

28

11. 10x

2 +

21x -

10

12. 9r2

+ 1

5r

+ 6

(

5n

- 7

)(3

n +

4)

(2x +

5)(

5x -

2)

3(3

r +

2)(

r +

1)

13. 12y

2 -

4y -

5

14. 14k

2 -

9k

- 1

8

15. 8z2

+ 2

0z

- 4

8

(

2y +

1)(

6y -

5)

(2

k -

3)(

7k

+ 6

) 4

(z +

4)(

2z -

3)

16. 12q

2 +

34q

- 2

8

17. 18h

2 +

15h

- 1

8

18. 12p

2 -

22p

- 2

0

2

(3q

- 2

)(2

q +

7)

3(2

h +

3)(

3h

- 2

) 2

(3p

+ 2

)(2

p -

5)

So

lve e

ach

eq

ua

tio

n.

Ch

eck

th

e s

olu

tio

ns.

19. 3h

2 +

2h

- 1

6 =

0

20. 15n

2 -

n =

2

21. 8q

2 -

10q +

3 =

0

{-

8

3 ,

2}

{-

1

3 ,

2

5 }

{ 1

2 ,

3

4 }

22. 6b

2 -

5b =

4

23. 10r2

- 2

1r

= -

4r

+ 6

24. 10g

2 +

10 =

29g

{-

1

2 ,

4

3 }

{-

3

10 ,

2}

{ 2

5 ,

5

2 }

25. 6y

2 =

-7y -

2

26. 9z2

= -

6z

+ 1

5

27. 12k

2 +

15k

= 1

6k +

20

{-

2

3 , -

1

2 }

{-

5

3 ,

1}

{-

5

4 ,

4

3 }

28. 12x

2 -

1 =

-x

29. 8a

2 -

16a

= 6a

- 1

2

30. 18a

2 +

10a

= -

11a

+ 4

{-

1

3 ,

1

4 }

{ 3

4 ,

2}

{-

4

3 ,

1

6 }

31. D

IVIN

G L

au

ren

dove i

nto

a s

wim

min

g p

ool

from

a 1

5-f

oot-

hig

h d

ivin

g b

oard

wit

h a

n

init

ial

up

ward

velo

city

of

8 f

eet

per

seco

nd

. F

ind

th

e t

ime t

in

seco

nd

s it

took

Lau

ren

to

en

ter

the w

ate

r. U

se t

he m

od

el

for

vert

ical

moti

on

giv

en

by t

he e

qu

ati

on

h

= -

16t2

+ vt

+ s

, w

here

h i

s h

eig

ht

in f

eet,

t i

s ti

me i

n s

eco

nd

s, v

is

the i

nit

ial

up

ward

velo

city

in

feet

per

seco

nd

, an

d s

is

the i

nit

ial

heig

ht

in f

eet.

(Hint:

Let h

= 0

rep

rese

nt

the s

urf

ace

of

the p

ool.

) 1.2

5 s

32. B

ASEB

ALL B

rad

toss

ed

a b

ase

ball

in

th

e a

ir f

rom

a h

eig

ht

of

6 f

eet

wit

h a

n i

nit

ial

up

ward

velo

city

of

14 f

eet

per

seco

nd

. E

nri

qu

e c

au

gh

t th

e b

all

on

its

way d

ow

n a

t a p

oin

t 4 f

eet

above t

he g

rou

nd

. H

ow

lon

g w

as

the b

all

in

th

e a

ir b

efo

re E

nri

qu

e c

au

gh

t it

? U

se

the m

od

el

of

vert

ical

moti

on

fro

m E

xerc

ise 3

1.

1 s

8-4

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Lesson 8-4

Ch

ap

ter

8

27

Gle

ncoe A

lgeb

ra 1

Wo

rd

Pro

ble

m P

racti

ce

Qu

ad

rati

c E

qu

ati

on

s:

ax

2 +

bx +

c =

0

1. B

REA

K E

VEN

B

reak

ing e

ven

occ

urs

w

hen

th

e r

even

ues

for

a b

usi

ness

equ

al

the c

ost

. A

loca

l ch

ild

ren

’s m

use

um

st

ud

ied

th

eir

cost

s (w

ages,

ele

ctri

city

, etc

.) a

nd

reven

ues

from

paid

ad

mis

sion

. T

hey f

ou

nd

th

at

their

bre

ak

-even

tim

e i

s giv

en

by t

he e

qu

ati

on

2h

2-

2h

- 2

4 =

0,

wh

ere

h i

s th

e n

um

ber

of

hou

rs t

he

mu

seu

m i

s op

en

per

day.

How

man

y

hou

rs m

ust

th

e m

use

um

be o

pen

per

day

to r

each

th

e b

reak

even

poin

t?

4 h

ou

rs

2. C

AR

PEN

TR

Y M

iko w

an

ts t

o b

uil

d a

toy

box f

or

her

sist

er.

It

is t

o b

e 2

feet

hig

h,

an

d t

he w

idth

is

to b

e 3

feet

less

th

an

its

le

ngth

. If

it

need

s to

hold

a v

olu

me o

f 80 c

ubic

feet,

fin

d t

he l

en

gth

an

d w

idth

of

the b

ox.

len

gth

= 8

ft;

wid

th =

5 f

t

3. FU

RN

ITU

RE

T

he s

tud

en

t co

un

cil

wan

ts

to p

urc

hase

a t

able

for

the s

chool

lobby.

Th

e t

able

com

es

in a

vari

ety

of

dim

en

sion

s, b

ut

for

every

table

, th

e

len

gth

is

1 m

ete

r gre

ate

r th

an

tw

ice t

he

wid

th.

Th

e s

tud

en

t co

un

cil

has

bu

dgete

d

for

a t

able

top

wit

h a

n a

rea o

f exact

ly

3 s

qu

are

mete

rs.

Fin

d t

he w

idth

an

d l

en

gth

of

the t

able

th

ey c

an

pu

rch

ase

. w

idth

= 1

m;

len

gth

= 3

m

4. LA

DD

ER

S A

lad

der

is r

est

ing a

gain

st a

w

all

. T

he t

op

of

the l

ad

der

tou

ches

the

wall

at

a h

eig

ht

of

15 f

eet,

an

d t

he l

en

gth

of

the l

ad

der

is o

ne f

oot

more

th

an

tw

ice

its

dis

tan

ce f

rom

th

e w

all

. F

ind

th

e

dis

tan

ce f

rom

th

e w

all

to t

he b

ott

om

of

the l

ad

der.

(Hint:

Use

th

e P

yth

agore

an

T

heore

m t

o s

olv

e t

he p

roble

m.)

8 f

t

15 ft.

Wall

Ladder

5. FA

RM

ING

M

r. H

en

sley h

as

a t

ota

l of

480 s

qu

are

feet

of

sheet

meta

l w

ith

w

hic

h h

e w

ou

ld l

ike t

o c

on

stru

ct a

cy

lin

dri

cal

tan

k f

or

stori

ng g

rain

. T

he

loca

l zon

ing l

aw

lim

its

the h

eig

ht

of

the

tan

k t

o 1

3.5

feet.

Reca

ll t

hat

a f

orm

ula

fo

r th

e s

urf

ace

are

a o

f a b

ott

om

less

cy

lin

der

wit

h r

ad

ius r

an

d h

eig

ht h

is

A =

πr2

+ 2

πrh

.

a.

Wri

te a

qu

ad

rati

c equ

ati

on

(se

t equ

al

to z

ero

) to

rep

rese

nt

the i

nfo

rmati

on

.

0 =

πr2

+ 2

r -

480

b.

Usi

ng 3

as

an

ap

pro

xim

ati

on

for

π,

solv

e t

he e

qu

ati

on

for r.

{5

, -

32}

c.

Wh

at

rad

ius

shou

ld M

r. H

en

sley u

se

for

his

tan

k?

5 f

t

8-4

2w

+1

w

Answers (Lesson 8-4)

Page 13: Answers (Anticipation Guide and Lesson 8-1) © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers Chapter 8 A3 Glencoe Algebra 1 Copyright © Glencoe/McGraw-Hill,

Answers

Co

pyri

gh

t ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f T

he M

cG

raw

-Hill C

om

pan

ies,

Inc.

Chapter 8 A13 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

8

28

Gle

ncoe A

lgeb

ra 1

En

rich

men

t

Are

a M

od

els

fo

r Q

uad

rati

c T

rin

om

ials

Aft

er

you

have f

act

ore

d a

qu

ad

rati

c tr

inom

ial,

you

can

use

th

e f

act

ors

to

dra

w g

eom

etr

ic m

od

els

of

the t

rin

om

ial.

x

2 +

5x -

6 =

(x -

1)(

x +

6)

To d

raw

a r

ect

an

gu

lar

mod

el,

th

e v

alu

e 2

w

as

use

d f

or

x s

o t

hat

the s

hort

er

sid

e w

ou

ld

have a

len

gth

of

1.

Th

en

th

e d

raw

ing w

as

don

e i

n c

en

tim

ete

rs.

So,

the a

rea o

f th

e

rect

an

gle

is

x2 +

5x -

6.

To d

raw

a r

igh

t tr

ian

gle

mod

el,

reca

ll t

hat

th

e a

rea o

f a t

rian

gle

is

on

e-h

alf

th

e b

ase

ti

mes

the h

eig

ht.

So,

on

e o

f th

e s

ides

mu

st

be t

wic

e a

s lo

ng a

s th

e s

hort

er

sid

e o

f th

e

rect

an

gu

lar

mod

el.

x2 +

5x -

6 =

(x -

1)(

x +

6)

= 1

2 (

2x -

2)(

x +

6)

Th

e a

rea o

f th

e r

igh

t tr

ian

gle

is

als

o x

2 +

5x -

6.

Fa

cto

r e

ach

trin

om

ial.

Th

en

fo

llo

w t

he d

irecti

on

s t

o d

ra

w e

ach

mo

del

of

the t

rin

om

ial.

1. x

2 +

2x -

3 U

se x

= 2

. D

raw

a

2. 3

x2 +

5x -

2 U

se x

= 1

. D

raw

a

rect

an

gle

in

cen

tim

ete

rs.

re

ctan

gle

in

cen

tim

ete

rs.

(x

+ 2

)(3x -

1)

(

x +

3)(

x -

1)

3. x

2 -

4x +

3 U

se x

= 4

. D

raw

tw

o d

iffe

ren

t ri

gh

t tr

ian

gle

s in

cen

tim

ete

rs.

(x

- 1

)(x -

3)

4. 9

x2 -

9x +

2 U

se x

= 2

. D

raw

tw

o d

iffe

ren

t ri

gh

t tr

ian

gle

s.

Use

0.5

cen

tim

ete

r fo

r each

un

it.

(3x -

2)(

3x -

1)

3x

- 2

6x

- 2

3x

- 1

6x

- 4

2x

- 6

x-

1

x-

3

2x

- 2

3x

- 1

x+

2

x-

1

x+

3

x+

6

2x

- 2

x+

6

x-

1

8-4

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Lesson 8-4

Ch

ap

ter

8

29

Gle

ncoe A

lgeb

ra 1

Gra

ph

ing C

alc

ula

tor

Act

ivit

y

Usin

g T

ab

les i

n F

acto

rin

g b

y G

rou

pin

g

Th

e T

AB

LE f

eatu

re c

an

be u

sed

to h

elp

fact

or

a p

oly

nom

ial

by f

ind

ing t

he f

act

ors

of

a c

ert

ain

p

rod

uct

, w

hic

h h

ave a

sp

eci

fic

sum

.

F

acto

r 1

0x

2-

43x

+ 2

8 b

y g

ro

up

ing

.

Mak

e a

table

of

the n

egati

ve f

act

ors

of

10

! 2

8 o

r 280.

Look

for

a p

air

of

fact

ors

wh

ose

su

m i

s -

43.

En

ter

the e

qu

ati

on

y =

280

x

in

Y1 t

o f

ind

th

e f

act

ors

of

280.

Th

en

,

fin

d t

he s

um

of

the f

act

ors

usi

ng y

= 2

80

x

+ x

in

Y2.

Set

up

th

e t

able

to d

isp

lay t

he n

egati

ve f

act

ors

of

280 b

y s

ett

ing ∆

Tb

l =

to

-1.

Exam

ine t

he r

esu

lts.

Th

e l

ast

lin

e o

f th

e t

able

sh

ow

s th

at

-43x m

ay b

e r

ep

lace

d w

ith

-

8x

+ (

-35x).

10x

2 -

43x +

28 =

10x

2 -

8x +

(-

35

x)

+ 2

8

=

2x(5

x -

4)

+ (

-7)(

5x -

4)

=

(5

x -

4)(

2x -

7)

Th

us,

10

x2 -

43

x +

28 =

(5x -

4)(

2x -

7).

F

acto

r 1

2x

2 -

7x -

12.

Look

at

the f

act

ors

of

12

! -

12 o

r -

144 f

or

a p

air

wh

ose

su

m i

s -

7.

En

ter

an

equ

ati

on

to d

ete

rmin

e t

he f

act

ors

in

Y1 a

nd

an

equ

ati

on

to

fin

d t

he s

um

of

fact

ors

in

Y2.

Exam

ine t

he t

able

to f

ind

a s

um

of

-7.

12x

2 -

7x -

12

= 1

2x

2 +

9x +

(-

16x)

- 1

2

= 3

x(4

x +

3)

- 4

(4x +

3)

=

(4

x +

3)(

3x -

4)

Th

us,

12x

2 -

7x -

12 =

(4

x +

3)(

3x -

4).

Fa

cto

r e

ach

qu

ad

ra

tic p

oly

no

mia

l if

po

ssib

le.

1. x

2 +

29

x -

96

2. x

2 -

14

x -

51

3. 3

z2 +

16z

- 3

5

(y +

32)(

y -

3)

(x -

17)(

x +

3)

(3

z -

5)(

z +

7)

4. 4

y2 -

25y +

18

5. 6a

2 -

a -

15

6. 6m

2 +

13m

+ 6

p

rim

e

(3a

- 5

)(2a

+ 3

) (

2m

+ 3

)(3m

+ 2

)

7. 12z2

- z

- 6

8. 16y

2 +

40y +

25

9. 4b

2 +

24b

- 4

93

(

4z -

3)(

3z +

2)

(4y +

5)2

(

2b

+ 2

9)(

2b

- 1

7)

8-4

Exam

ple

1

Exam

ple

2

Exerc

ises

Answers (Lesson 8-4)

Page 14: Answers (Anticipation Guide and Lesson 8-1) © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers Chapter 8 A3 Glencoe Algebra 1 Copyright © Glencoe/McGraw-Hill,

Co

pyrig

ht ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f Th

e M

cG

raw

-Hill C

om

pan

ies, In

c.

Chapter 8 A14 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

8

30

Gle

ncoe A

lgeb

ra 1

Stu

dy

Gu

ide a

nd

In

terv

en

tio

n

Qu

ad

rati

c E

qu

ati

on

s:

Dif

fere

nces o

f S

qu

are

s

Fact

or

Dif

fere

nce

s o

f Sq

uare

s T

he b

inom

ial

exp

ress

ion

a2 -

b2 i

s ca

lled

th

e

dif

feren

ce o

f tw

o s

qu

ares.

Th

e f

oll

ow

ing p

att

ern

sh

ow

s h

ow

to f

act

or

the d

iffe

ren

ce o

f sq

uare

s.

F

acto

r e

ach

po

lyn

om

ial.

a. n

2 -

64

n

2 -

64

= n

2 -

82

Write

in t

he f

orm

a2 -

b2.

= (

n +

8)(

n -

8)

Facto

r.

b.

4m

2 -

81n

2

4m

2 -

81n

2

=

(2

m)2

- (

9n

)2

Write

in t

he f

orm

a2 -

b2.

=

(2

m -

9n

)(2

m +

9n

) F

acto

r.

F

acto

r e

ach

po

lyn

om

ial.

a.

50a

2 -

72

50a

2 -

72

=

2(2

5a

2 -

36)

Fin

d t

he G

CF

.

=

2[(

5a

)2 -

62)]

25

a2 =

5a

5a

and 3

6 =

6

6

=

2(5

a +

6)(

5a

- 6

) F

acto

r th

e d

iffe

rence o

f square

s.

b.

4x

4 +

8x

3 -

4x

2 -

8x

4

x4 +

8x

3 -

4x

2 -

8x

Origin

al poly

nom

ial

=

4x(x

3 +

2x

2 -

x -

2)

Fin

d t

he G

CF

.

=

4x[(

x3 +

2x

2) -

(x +

2)]

G

roup t

erm

s.

=

4x[x

2(x

+ 2

) -

1(x

+ 2

)]

Fin

d t

he G

CF

.

=

4x[(

x2 -

1)(

x +

2)]

F

acto

r by g

roupin

g.

=

4x[(

x -

1)(

x +

1)(

x +

2)]

Fa

cto

r th

e d

iffe

rence

of

square

s.

Exerc

ises

Fa

cto

r e

ach

po

lyn

om

ial.

1. x

2 -

81

2. m

2 -

100

3. 16

n2 -

25

(

x +

9)(

x -

9)

(m

+ 1

0)(

m -

10)

(4n

- 5

)(4

n +

5)

4. 36x

2 -

100

y2

5. 49x

2 -

36

6. 16

a2 -

9b

2

(

6x +

10y)(

6x -

10y)

(7x +

6)(

7x -

6)

(4a

- 3

b)(

4a

+ 3

b)

7. 225

b2 -

a2

8. 72p

2 -

50

9. -

2 +

2x

2

(

15b

- a

)(15b

+ a

) 2

(6p

+ 5

)(6p

- 5

) 2

(x -

1)(

x +

1)

10. -

81 +

a4

11. 6 -

54a

2

12. 8y

2 -

200

(

a -

3)(

a +

3)(

a2 +

9)

6(1

+ 3

a)(

1 -

3a

) 8

(y +

5)(

y -

5)

13. 4x

3 -

10

0x

14. 2y

4 -

32y

2

15. 8

m3 -

12

8m

4

x(x

+ 5

)(x -

5)

2y

2(y

+ 4

)(y -

4)

8m

(m +

4)(

m -

4)

16. 4x

2 -

25

17. 2a

3 -

98

ab

2

18. 18

y2 -

72

y4

(

2x +

5)(

2x -

5)

2a

(a -

7b

)(a

+ 7

b)

18

y2(1

- 2

y)(

1 +

2y)

19. 169x

3 -

x

20. 3

a4 -

3a

2

21. 3

x4 +

6x

3 -

3x

2 -

6x

x

(13x +

1)(

13

x -

1)

3a

2(a

+ 1

)(a

- 1

) 3

x(x

- 1

)(x +

1)(

x +

2)

8-5

Exam

ple

1Exam

ple

2

Dif

fere

nce o

f S

qu

are

sa

2 -

b2 =

(a

- b

)(a

+ b

) =

(a +

b)(

a -

b).

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Lesson 8-5

Ch

ap

ter

8

31

Gle

ncoe A

lgeb

ra 1

Stu

dy

Gu

ide a

nd

In

terv

en

tio

n

(con

tin

ued

)

Qu

ad

rati

c E

qu

ati

on

s:

Dif

fere

nces o

f S

qu

are

s

So

lve E

qu

ati

on

s b

y F

act

ori

ng

F

act

ori

ng a

nd

th

e Z

ero

Pro

du

ct P

rop

ert

y c

an

be u

sed

to

solv

e e

qu

ati

on

s th

at

can

be w

ritt

en

as

the p

rod

uct

of

an

y n

um

ber

of

fact

ors

set

equ

al

to 0

.

S

olv

e e

ach

eq

ua

tio

n.

Ch

eck

yo

ur s

olu

tio

ns.

a. x

2 -

1 −

25 =

0

x2 -

1

25 =

0

Origin

al equation

x2 -

( 1

5 ) 2

= 0

x

2 =

x ·

x a

nd

1

25 =

( 1

5 ) (

1

5 )

(x

+ 1

5 ) (x

- 1

5 ) =

0

Facto

r th

e d

iffe

rence o

f square

s.

x +

1

5 =

0

or

x -

1

5 =

0

Zero

Pro

duct

Pro

pert

y

x =

- 1

5

x =

1

5

Solv

e e

ach e

quation.

Th

e s

olu

tion

set

is {-

1

5 ,

1

5 } .

Sin

ce (-

1

5 ) 2

-

1

25 =

0 a

nd

( 1

5 ) 2

-

1

25 =

0,

the s

olu

tion

s ch

eck

.

b.

4x

3 =

9x

4

x3 =

9x

Origin

al equation

4x

3 -

9x =

0

Subtr

act

9x f

rom

each s

ide.

x(4

x2 -

9) =

0

Fin

d t

he G

CF

.

x[(

2x)2

- 3

2] =

0

4x

2 =

2x

2x a

nd 9

= 3

3

x[(

2x)2

- 3

2] =

x[(

2x -

3)(

2x +

3)]

F

acto

r th

e d

iffe

rence o

f square

s.

x =

0 or

(2

x -

3) =

0 or

(2

x +

3) =

0

Zero

Pro

duct

Pro

pert

y

x =

0

x =

3

2

x =

- 3

2

Solv

e e

ach e

quation.

Th

e s

olu

tion

set

is {0

, 3

2 , -

3

2 } .

Sin

ce 4

(0)3

= 9

(0),

4 ( 3

2 ) 3

= 9

( 3

2 ) ,

an

d 4

(- 3

2 ) 3

= 9

(- 3

2 ) ,

the s

olu

tion

s ch

eck

.

So

lve e

ach

eq

ua

tio

n b

y f

acto

rin

g.

Ch

eck

th

e s

olu

tio

ns.

1. 81

x2 =

49 { 7

9 , -

7 −

9 }

2. 36n

2 =

1 {-

1 −

6 ,

1 −

6 }

3. 25

d2 -

100 =

0 {2

, -

2}

4. 1

4 x

2 =

25

{1

0, -

10}

5. 36 =

1

25 x

2 {-

30,

30}

6. 4

9

100 -

x2

= 0

{-

7 −

10 ,

7 −

10 }

7. 9

x3 =

25x {0

, -

5 −

3 ,

5 −

3 }

8. 7

a3 =

175a

{0

, -

5,

5}

9. 2

m3 =

32m

{0

, -

4,

4}

10. 16y

3 =

25y {0

, -

5 −

4 ,

5 −

4 }

11. 1

64 x

2 =

49 {-

56,

56}

12. 4

a3 -

64a

= 0

{0

, -

4,

4}

13. 3

b3 -

27b

= 0

{0

, -

3,

3}

14. 9

25 m

2 =

121 {-

55 −

3 ,

55 −

3 }

15. 48n

3 =

147

n {0

, -

7 −

4 ,

7 −

4 }

8-5

Exerc

ises

Exam

ple

Answers (Lesson 8-5)

Page 15: Answers (Anticipation Guide and Lesson 8-1) © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers Chapter 8 A3 Glencoe Algebra 1 Copyright © Glencoe/McGraw-Hill,

Answers

Co

pyri

gh

t ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f T

he M

cG

raw

-Hill C

om

pan

ies,

Inc.

Chapter 8 A15 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

8

32

Gle

ncoe A

lgeb

ra 1

Sk

ills

Practi

ce

Qu

ad

rati

c E

qu

ati

on

s:

Dif

fere

nces o

f S

qu

are

s

Fa

cto

r e

ach

po

lyn

om

ial,

if

po

ssib

le.

If t

he p

oly

no

mia

l ca

nn

ot

be f

acto

red

,

writ

e prim

e.

1. a

2 -

4

2. n

2 -

64

(

a +

2)(

a -

2)

(n

+ 8

)(n

- 8

)

3. 1 -

49

d2

4. -

16 +

p2

(

1 +

7d

)(1 -

7d

) (

p +

4)(

p -

4)

5. k

2 +

25

6. 36 -

100w

2

p

rim

e

(6 -

10

w)(

6 +

10w

)

7. t2

- 8

1u

2

8. 4

h2 -

25

g2

(

t +

9u

)(t -

9u

) (

2h

+ 5

g)(

2h

- 5

g)

9. 64m

2 -

9y

2

10. 4

c2 -

5d

2

(

8m

- 3

y)(

8m

+ 3

y)

pri

me

11. -

49r2

+ 4

t2

12. 8

x2 -

72p

2

(

2t +

7r)

(2t -

7r)

8

(x +

3p

)(x -

3p

)

13. 20q

2 -

5r2

14. 32a

2 -

50b

2

5

(2q

+ r

)(2

q -

r)

2(4

a +

5b

)(4

a -

5b

)

So

lve e

ach

eq

ua

tio

n b

y f

acto

rin

g.

Ch

eck

th

e s

olu

tio

ns.

15. 16x

2 -

9 =

0 {±

3

4 }

16. 25p

2 -

16 =

0 {±

4

5 }

17. 36q

2 -

49

= 0

7

6 }

18. 81 -

4b

2 =

0 {±

9

2 }

19. 16d

2 =

4 {±

1

2 }

20. 18a

2 =

8 {±

2

3 }

21. n

2 -

9

25 =

0 {±

3

5 }

22. k

2 -

49 −

64 =

0 {±

7

8 }

23. 1

25 h

2 -

16 =

0 {±

20}

24. 1

16 y

2 =

81 {±

36}

8-5

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Lesson 8-5

Ch

ap

ter

8

33

Gle

ncoe A

lgeb

ra 1

Practi

ce

Qu

ad

rati

c E

qu

ati

on

s:

Dif

fere

nces o

f S

qu

are

s

Fa

cto

r e

ach

po

lyn

om

ial,

if

po

ssib

le.

If t

he p

oly

no

mia

l ca

nn

ot

be f

acto

red

, w

rit

e

prim

e.

1. k

2 -

10

0

2. 81 -

r2

3. 16

p2 -

36

(

k +

10)(

k -

10)

(9 +

r)(

9 -

r)

(4

p +

6)(

4p

- 6

)

4. 4x

2 +

25

5. 144 -

9f 2

6. 36

g2 -

49

h2

p

rim

e

(12 +

3f)(

12 -

3f)

(6

g +

7h

)(6g

- 7

h)

7. 121m

2 -

14

4p

2

8. 32 -

8y

2

9. 24

a2 -

54

b2

(

11m

- 1

2p

)(11

m +

12p

) 8

(2 -

y)(

2 +

y)

6(2

a -

3b

)(2a

+ 3

b)

10. 32t2

- 1

8u

2

11. 9d

2 -

32

12. 36z3

- 9

z

2

(4t -

3u

)(4t +

3u

) p

rim

e

9z

(2z +

1)(

2z -

1)

13. 45q

3 -

20q

14. 100

b3 -

36

b

15. 3

t4 -

48t2

5

q(3

q +

2)(

3q

- 2

) 4

b(5

b +

3)(

5b

- 3

) 3

t2(t

+ 4

)(t -

4)

So

lve e

ach

eq

ua

tio

n b

y f

acto

rin

g.

Ch

eck

yo

ur s

olu

tio

ns.

16. 4y

2 =

81

17. 64p

2 =

9

18. 98b

2 -

50 =

0

{± 9

2 }

{± 3

8 }

{± 5

7 }

19. 32 -

162

k2 =

0

20. t2

-

64 −

121 =

0

21. 1

6 −

49 -

v2 =

0

{± 4

9 }

{± 8

11 }

{± 4

7 }

22.

1 −

36 x

2 -

25 =

0

23. 27h

3 =

48h

24. 75

g3 =

14

7g

30}

{± 4

3 ,

0}

{± 7

5 ,

0}

25. ER

OSIO

N A

rock

bre

ak

s lo

ose

fro

m a

cli

ff a

nd

plu

nges

tow

ard

th

e g

rou

nd

400 f

eet

belo

w.

Th

e d

ista

nce

d t

hat

the r

ock

fall

s in

t s

eco

nd

s is

giv

en

by t

he e

qu

ati

on

d =

16t2

.

How

lon

g d

oes

it t

ak

e t

he r

ock

to h

it t

he g

rou

nd

? 5 s

26. FO

REN

SIC

S M

r. C

oop

er

con

test

ed

a s

peed

ing t

ick

et

giv

en

to h

im a

fter

he a

pp

lied

his

bra

kes

an

d s

kid

ded

to a

halt

to a

void

hit

tin

g a

noth

er

car.

In

tra

ffic

cou

rt,

he a

rgu

ed

th

at

the l

en

gth

of

the s

kid

mark

s on

th

e p

avem

en

t, 1

50 f

eet,

pro

ved

th

at

he w

as

dri

vin

g

un

der

the p

ost

ed

sp

eed

lim

it o

f 65 m

iles

per

hou

r. T

he t

ick

et

cite

d h

is s

peed

at

70 m

iles

per

hou

r. U

se t

he f

orm

ula

1 −

24 s

2 =

d,

wh

ere

s i

s th

e s

peed

of

the c

ar

an

d d

is

the l

en

gth

of

the s

kid

mark

s, t

o d

ete

rmin

e M

r. C

oop

er’

s sp

eed

wh

en

he a

pp

lied

th

e b

rak

es.

Was

Mr.

Coop

er

corr

ect

in

cla

imin

g t

hat

he w

as

not

speed

ing w

hen

he a

pp

lied

th

e b

rak

es?

60 m

ph

; yes

8-5

Answers (Lesson 8-5)

Page 16: Answers (Anticipation Guide and Lesson 8-1) © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers Chapter 8 A3 Glencoe Algebra 1 Copyright © Glencoe/McGraw-Hill,

Co

pyrig

ht ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f Th

e M

cG

raw

-Hill C

om

pan

ies, In

c.

Chapter 8 A16 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

8

34

Gle

ncoe A

lgeb

ra 1

Wo

rd

Pro

ble

m P

racti

ce

Qu

ad

rati

c E

qu

ati

on

s:

Dif

fere

nces o

f S

qu

are

s

1. LO

TTER

Y A

sta

te l

ott

ery

com

mis

sion

an

aly

zes

the t

ick

et

pu

rch

asi

ng p

att

ern

s of

its

citi

zen

s. T

he f

oll

ow

ing e

xp

ress

ion

is

develo

ped

to h

elp

off

icia

ls c

alc

ula

te t

he

lik

ely

nu

mber

of

peop

le w

ho w

ill

bu

y

tick

ets

for

a c

ert

ain

siz

e j

ack

pot.

81

a2-

36

b2

Fact

or

the e

xp

ress

ion

com

ple

tely

.

3(3

a+

2b

) (3

a-

2b

)

2. O

PTIC

S A

refl

ect

or

on

th

e i

nsi

de o

f a

cert

ain

fla

shli

gh

t is

a p

ara

bola

giv

en

by

the e

qu

ati

on

y=

x2-

25.

Fin

d t

he p

oin

ts

wh

ere

th

e r

efl

ect

or

meets

th

e l

en

s by

fin

din

g t

he v

alu

es

of

x w

hen

y=

0.

5, -

5

3. A

RC

HIT

EC

TU

RE

T

he d

raw

ing s

how

s a

tria

ngu

lar

roof

tru

ss w

ith

a b

ase

m

easu

rin

g t

he s

am

e a

s it

s h

eig

ht.

Th

e

are

a o

f th

e t

russ

is

98 s

qu

are

mete

rs.

Fin

d t

he h

eig

ht

of

the t

russ

. 14 m

4. B

ALLO

ON

ING

T

he f

un

ctio

n

f (t)

=-

16t2+

576 r

ep

rese

nts

th

e h

eig

ht

of

a f

reely

fall

ing b

all

ast

bag t

hat

start

s fr

om

rest

on

a b

all

oon

576 f

eet

above t

he

gro

un

d.

Aft

er

how

man

y s

eco

nd

s t

does

the b

all

ast

bag h

it t

he g

rou

nd

?

aft

er

6 s

eco

nd

s

5. D

EC

OR

ATIN

G M

arv

in w

an

ts t

o

pu

rch

ase

a r

ect

an

gu

lar

rug.

It h

as

an

are

a o

f 80 s

qu

are

feet.

He c

an

not

rem

em

ber

the l

en

gth

an

d w

idth

, bu

t h

e

rem

em

bers

th

at

the l

en

gth

was

8 m

ore

th

an

som

e n

um

ber

an

d t

he w

idth

was

8 l

ess

th

an

th

at

sam

e n

um

ber.

a

. Wri

te a

qu

ad

rati

c equ

ati

on

usi

ng t

he

info

rmati

on

giv

en

. x

2-

64 =

80 o

r x

2-

144 =

0

b

. Wh

at

are

th

e l

en

gth

an

d w

idth

of

the

rug?

20 f

t an

d 4

ft

Are

a =

98m

2he

ight

base

x+

8

x-

8

8-5

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Lesson 8-5

Ch

ap

ter

8

35

Gle

ncoe A

lgeb

ra 1

En

ric

hm

en

t

Facto

rin

g T

rin

om

ials

of

Fo

urt

h D

eg

ree

Som

e t

rin

om

ials

of

the f

orm

a4 +

a2b

2 +

b4 c

an

be w

ritt

en

as

the

dif

fere

nce

of

two s

qu

are

s an

d t

hen

fact

ore

d.

F

acto

r 4x

4 -

37x

2y

2 +

9y

4.

Ste

p 1

F

ind

th

e s

qu

are

roots

of

the f

irst

an

d l

ast

term

s.

√ ""

4x

4 =

2x

2

√ ""

9y

4 =

3y

2

Ste

p 2

F

ind

tw

ice t

he p

rod

uct

of

the s

qu

are

roots

.

2(2

x2)(

3y

2) =

12

x2y

2

Ste

p 3

S

ep

ara

te t

he m

idd

le t

erm

in

to t

wo p

art

s. O

ne p

art

is

eit

her

you

r an

swer

to S

tep

2 o

r it

s op

posi

te.

Th

e o

ther

part

sh

ou

ld b

e

the o

pp

osi

te o

f a p

erf

ect

squ

are

.

-

37x

2y

2 =

-12x

2y

2 -

25x

2y

2

Ste

p 4

R

ew

rite

th

e t

rin

om

ial

as

the d

iffe

ren

ce o

f tw

o s

qu

are

s an

d

then

fact

or.

4x

4 -

37x

2y

2 +

9y

4 =

(4

x4 -

12x

2y

2 +

9y

4) -

25x

2y

2

= (

2x

2 -

3y

2)2

- 2

5x

2y

2

= [

(2x

2 -

3y

2) +

5xy][

(2x

2 -

3y

2) -

5xy]

= (

2x

2 +

5xy -

3y

2)(

2x

2 -

5xy -

3y

2)

Fa

cto

r e

ach

po

lyn

om

ial.

1. x

4 +

x2y

2 +

y4

2. x

4 +

x2 +

1

(

x2 + x

y +

y2)(

x2 -

xy +

y2)

(x

2 +

x +

1)(

x2 -

x +

1)

3. 9

a4 -

15a

2 +

1

4. 16a

4 -

17a

2 +

1

(

3a

2 +

3a

- 1

)(3

a2 -

3a -

1)

(4

a -

1)(

a +

1)(

4a

+ 1

)(a

- 1

)

5. 4

a4 -

13a

2 +

1

6. 9

a4 +

26a

2b

2 +

25

b4

(

2a

2 +

3a -

1)(

2a

2 -

3a -

1)

(3

a2 +

2ab

+ 5

b2)(

3a

2 -

2ab

+ 5

b2)

7. 4

x4 -

21x

2y

2 +

9y

4

8. 4

a4 -

29a

2b

2 +

25

b4

(

2x

2 +

3xy -

3y

2)(

2x

2 -

3xy -

3y

2)

(2

a +

5b

)(a

- b

)(2

a -

5b

)(a

+ b

)

8-5 Exam

ple

Answers (Lesson 8-5)

Page 17: Answers (Anticipation Guide and Lesson 8-1) © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers Chapter 8 A3 Glencoe Algebra 1 Copyright © Glencoe/McGraw-Hill,

Answers

Co

pyri

gh

t ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f T

he M

cG

raw

-Hill C

om

pan

ies,

Inc.

Chapter 8 A17 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

8

36

Gle

ncoe A

lgeb

ra 1

Sp

read

sheet

Act

ivit

y

Dif

fere

nces o

f S

qu

are

s

Th

ere

is

a s

peci

al

patt

ern

you

can

use

to f

act

or

bin

om

ials

of

the f

orm

a2 -

b2.

You

can

use

a s

pre

ad

sheet

to d

isco

ver

this

rela

tion

ship

.

U

se a

sp

rea

dsh

eet

to i

nv

esti

ga

te t

he v

alu

es o

f th

e e

xp

ress

ion

s (a

2 -

b2),

(a

- b

)2, (a

- b

)(a

+ b

), a

nd

(a

+ b

)2. W

ha

t co

nje

ctu

re c

an

yo

u m

ak

e a

bo

ut

the e

xp

ressio

ns?

Ste

p 1

Y

ou

wil

l u

se C

olu

mn

s A

an

d B

to e

nte

r vari

ou

s valu

es

that

you

ch

oose

for a

an

d b

.

Ste

p 2

E

nte

r th

e f

orm

ula

s fo

r (a

2 -

b2),

(a

- b

)2,

(a -

b)(a

+ b

), a

nd

(a

+ b

)2

in C

olu

mn

s C

, D

, E

, an

d F

. T

o e

nte

r an

exp

on

en

t, u

se t

he s

ym

bol

^

foll

ow

ed

by t

he e

xp

on

en

t. F

or

exam

ple

, th

e s

qu

are

of

the v

alu

e i

n

cell

A2 i

s en

tere

d a

s A

2^

2.

1. E

nte

r vari

ou

s valu

es

of a

an

d b

in

Colu

mn

s A

an

d B

. L

ook

for

a p

att

ern

. W

hat

do y

ou

obse

rve a

bou

t th

e e

xp

ress

ion

s? F

or

an

y v

alu

es o

f a

an

d b

, (a

2 -

b2) =

(a -

b)(

a +

b).

2. F

ind

th

e p

rod

uct

s of

(a -

b)2

, (a

- b

)(a

+ b

), a

nd

(a

+ b

)2.

Do t

he r

esu

lts

veri

fy y

ou

r co

nje

ctu

re?

(a -

b)2

= a

2 -

2ab

+ b

2;

(a -

b)(

a +

b) =

a

2 -

b2;

an

d (

a +

b)2

= a

2 +

2ab

+ b

2;

yes

Use t

he p

att

ern

yo

u o

bserv

ed

to

fa

cto

r e

ach

bin

om

ial.

3. m

2 -

t2

4. x

2 -

4

5. y

2 -

16

(

m -

t)(

m +

t)

(x -

2)(

x +

2)

(y -

4)(

y +

4)

6. q

2 -

121

7. r2

- 1

69

8. b

2 -

1

(q

- 1

1)(

q +

11)

(r -

13)(

r +

13)

(b

- 1

)(b

+ 1

)

9. 4x

2 -

1

10. 16t2

- r

2

11. 25a

2 -

81d

2

(

2x -

1)(

2x +

1)

(4

t -

r)(

4t +

r)

(5a

- 9

d)(

5a +

9d

)

A

1 2 3 4 5

BC

DE

Fa^

2 -

b^

2(a

- b

)(a +

b)

(a -

b)^

2(a

+ b

)^2

ab

=(A

2-

B2)^

2=

A2^2-

B2^2

=(A

2-

B2)*

(A2+

B2)

=(A

2+

B2)^

2

=(A

3-

B3)^

2=

A3^2-

B3^2

=(A

3-

B3)*

(A3+

B3)

=(A

3+

B3)^

2

=(A

4-

B4)^

2=

A4^2-

B4^2

=(A

4-

B4)*

(A4+

B4)

=(A

4+

B4)^

2

Sh

eet

1S

heet

2S

heet

3

8-5

Exerc

ises

Exam

ple

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Lesson 8-6

Ch

ap

ter

8

37

Gle

ncoe A

lgeb

ra 1

Fact

or

Perf

ect

Sq

uare

Tri

no

mia

ls

Th

e p

att

ern

s sh

ow

n b

elo

w c

an

be u

sed

to f

act

or

perf

ect

squ

are

tri

nom

ials

.

Stu

dy

Gu

ide a

nd

In

terv

en

tio

n

Qu

ad

rati

c E

qu

ati

on

s:

Perf

ect

Sq

uare

s

D

ete

rm

ine w

heth

er

16n

2 -

24n

+ 9

is a

perfe

ct

sq

ua

re

trin

om

ial.

If

so

, fa

cto

r i

t.

Sin

ce 1

6n

2 =

(4n

)(4n

), t

he f

irst

term

is

a

perf

ect

squ

are

.

Sin

ce 9

= 3

! 3

, th

e l

ast

term

is

a p

erf

ect

sq

uare

.

Th

e m

idd

le t

erm

is

equ

al

to 2

(4n

)(3).

Th

ere

fore

, 16n

2 -

24n

+ 9

is

a p

erf

ect

sq

uare

tri

nom

ial.

16n

2 -

24n

+ 9

= (

4n

)2 -

2(4n

)(3)

+ 3

2

=

(4n

- 3

)2

F

acto

r 1

6x

2 -

32x +

15.

Sin

ce 1

5 i

s n

ot

a p

erf

ect

squ

are

, u

se a

dif

fere

nt

fact

ori

ng p

att

ern

.

16x

2 -

32x +

15

O

rigin

al tr

inom

ial

=

16x

2 +

mx +

px +

15

Write

the p

attern

.

=

16x

2 -

12x -

20x +

15

m =

-12 a

nd p

= -

20

=

(1

6x

2 -

12x)

- (

20x -

15)

Gro

up t

erm

s.

=

4x(4x -

3)

- 5

(4x -

3)

Fin

d t

he G

CF

.

=

(4x -

5)(

4x -

3)

Facto

r by g

roupin

g.

Th

ere

fore

16x

2 -

32x +

15

= (

4x -

5)(

4x -

3).

Exerc

ises

Dete

rm

ine w

heth

er e

ach

trin

om

ial

is a

perfe

ct

sq

ua

re t

rin

om

ial.

Writ

e yes o

r no

. If

so

, fa

cto

r i

t.

1. x

2 -

16x +

64

2. m

2 +

10m

+ 2

5

3. p

2 +

8p

+ 6

4

y

es;

(x -

8)(

x -

8)

yes;

(m +

5)(

m +

5)

no

Fa

cto

r e

ach

po

lyn

om

ial,

if

po

ssib

le.

If t

he p

oly

no

mia

l ca

nn

ot

be f

acto

red

, w

rit

e

prim

e.

4. 98x

2 -

20

0y

2

5. x

2 +

22x +

121

6. 81 +

18j

+ j

2

2

(7x +

10y)(

7x -

10

y)

(x +

11)2

(

9 +

j)2

7. 25c2

- 1

0c

- 1

8. 169 -

26r

+ r

2

9. 7x

2 -

9x +

2

p

rim

e

(13 -

r)2

(

7x -

2)(

x -

1)

10. 16m

2 +

48m

+ 3

6

11. 16 -

25a

2

12. b

2 -

16b

+ 2

56

4

(2m

+ 3

)2

(4 +

5a

)(4 -

5a

) p

rim

e

13. 36x

2 -

12x +

1

14. 16a

2 -

40ab

+ 2

5b

2

15. 8m

3 -

64m

(

6x -

1)2

(

4a

- 5

b)2

8

m(m

2 -

8)

8-6

Exam

ple

1Exam

ple

2

Perf

ect

Sq

uare

Tri

no

mia

la t

rinom

ial of

the f

orm

a2 +

2ab

+ b

2 o

r a

2 -

2ab

+ b

2

Sq

uari

ng

a B

ino

mia

lF

acto

rin

g a

Perf

ect

Sq

uare

Tri

no

mia

l

(a +

4)2

= a

2 +

2(a

)(4)

+ 4

2

=

a2 +

8a +

16

a2 +

8a +

16

= a

2 +

2(a

)(4)

+ 4

2

=

(a +

4)2

(2x -

3)2

= (

2x)2

-2(2

x)(

3)

+ 3

2

=

4x

2 -

12x +

9

4x

2 -

12x +

9 =

(2x)2

-2(2

x)(

3)

+ 3

2

=

(2x -

3)2

Answers (Lesson 8-5 and Lesson 8-6)

Page 18: Answers (Anticipation Guide and Lesson 8-1) © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers Chapter 8 A3 Glencoe Algebra 1 Copyright © Glencoe/McGraw-Hill,

Co

pyrig

ht ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f Th

e M

cG

raw

-Hill C

om

pan

ies, In

c.

Chapter 8 A18 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

8

38

Gle

ncoe A

lgeb

ra 1

Stu

dy

Gu

ide a

nd

In

terv

en

tio

n

(con

tin

ued

)

Qu

ad

rati

c E

qu

ati

on

s:

Perf

ect

Sq

uare

s

So

lve E

qu

ati

on

s w

ith

Perf

ect

Sq

uare

s F

act

ori

ng a

nd

th

e Z

ero

Pro

du

ct P

rop

ert

y

can

be u

sed

to s

olv

e e

qu

ati

on

s th

at

involv

e r

ep

eate

d f

act

ors

. T

he r

ep

eate

d f

act

or

giv

es

just

on

e s

olu

tion

to t

he e

qu

ati

on

. Y

ou

may a

lso b

e a

ble

to u

se t

he s

qu

are r

oo

t p

ro

perty

belo

w

to s

olv

e c

ert

ain

equ

ati

on

s.

S

olv

e e

ach

eq

ua

tio

n.

Ch

eck

yo

ur s

olu

tio

ns.

a. x

2 -

6x +

9 =

0

x

2 -

6x +

9 =

0

Origin

al equation

x

2 -

2(3

x) +

32 =

0

Recogniz

e a

perf

ect

square

trinom

ial.

(x

- 3

)(x -

3) =

0

Facto

r th

e p

erf

ect

square

trinom

ial.

x -

3 =

0

Set

repeate

d f

acto

r equal to

0.

x =

3

Solv

e.

Th

e s

olu

tion

set

is {

3}.

Sin

ce 3

2 -

6(3

) +

9 =

0,

the s

olu

tion

ch

eck

s.

b.

(a -

5)2

= 6

4

(a

- 5

)2 =

64

O

rigin

al equation

a

- 5

= ± √ ##

64

Square

Root

Pro

pert

y

a

- 5

= ±

8

64 =

8 $

8

a

= 5

± 8

A

dd 5

to e

ach s

ide.

a

= 5

+ 8

or

a =

5 -

8

Separa

te into

2 e

quations.

a

= 1

3

a =

-3

Solv

e e

ach e

quation.

Th

e s

olu

tion

set

is {-

3,

13}.

Sin

ce (-

3 -

5)2

= 6

4 a

nd

(13 -

5)2

= 6

4,

the s

olu

tion

s ch

eck

.

So

lve e

ach

eq

ua

tio

n.

Ch

eck

th

e s

olu

tio

ns.

1. x

2 +

4x +

4 =

0 {-

2}

2. 16n

2 +

16

n +

4 =

0 {- 1

2 }

3. 25d

2 -

10

d +

1 =

0 { 1

5 }

4. x

2 +

10x +

25

= 0

{-

5}

5. 9

x2 -

6x +

1 =

0 { 1

3 }

6. x

2 +

x +

1 −

4 =

0 {- 1

2 }

7. 25k

2 +

20

k +

4 =

0 {- 2

5 }

8. p

2 +

2p

+ 1

= 4

9

9. x

2 +

4x +

4 =

64

{-

8,

6}

{-

10,

6}

10. x

2 -

6x +

9 =

25

{-

2,

8}

11. a

2 +

8a

+ 1

6 =

1

12. 16

y2 +

8y +

1 =

0 {- 1

4 }

{-

3, -

5}

13. (x

+ 3

)2 =

49 {-

10,

4}

14. (y

+ 6

)2 =

1 {-

7, -

5}

15. (m

- 7

)2 =

49

{0

, 14}

16. (2

x +

1)2

= 1

{-

1,

0}

17. (4

x +

3)2

= 2

5 {-

2,

1 −

2 }

18. (3

h -

2)2

= 4

{ 4

3 ,

0}

19. (x

+ 1

)2 =

7

20. (y

- 3

)2 =

6

21. (m

- 2

)2 =

5

{-

1 ±

√ $

7 }

{3 ±

√ %

6 }

{2 ±

√ %

5 }

8-6

Exerc

ises

Sq

uare

Ro

ot

Pro

pert

yF

or

any n

um

ber

n >

0,

if x

2 =

n,

then x

= ± √ #

n .

Exam

ple

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Lesson 8-6

Ch

ap

ter

8

39

Gle

ncoe A

lgeb

ra 1

Sk

ills

Pra

ctic

e

Qu

ad

rati

c E

qu

ati

on

s:

Perf

ect

Sq

uare

s

Dete

rm

ine w

heth

er e

ach

trin

om

ial

is a

perfe

ct

sq

ua

re t

rin

om

ial.

Writ

e yes o

r no.

If s

o,

facto

r i

t.

1. m

2 -

6m

+ 9

2. r2

+ 4

r +

4

y

es;

(m -

3)2

y

es;

(r +

2)2

3. g

2 -

14g +

49

4. 2w

2 -

4w

+ 9

y

es;

(g -

7)2

n

o

5. 4

d2 -

4d

+ 1

6. 9

n2 +

30n

+ 2

5

y

es;

(2d

- 1

)2

yes;

(3n

+ 5

)2

Fa

cto

r e

ach

po

lyn

om

ial,

if

po

ssib

le.

If t

he p

oly

no

mia

l ca

nn

ot

be f

acto

red

, w

rit

e prim

e.

7. 2

x2 -

72

8. 6

b2 +

11b

+ 3

2

(x +

6)(

x -

6)

(2

b +

3)(

3b

+ 1

)

9. 36t2

- 2

4t +

4

10. 4

h2 -

56

4

(3t -

1)2

4

(h2 -

14)

11. 17a

2 -

24

ab

12. q

2 -

14

q +

36

a

(17a -

24

b)

pri

me

13. y

2 +

24y +

14

4

14. 6

d2 -

96

(

y +

12)2

6

(d -

4)(

d +

4)

So

lve e

ach

eq

ua

tio

n.

Ch

eck

th

e s

olu

tio

ns.

15. x

2 -

18x +

81 =

0 {9}

16. 4

p2 +

4p

+ 1

= 0

{- 1

2 }

17. 9g

2 -

12g +

4 =

0 { 2

3 }

18. y

2 -

16y +

64 =

81 {-

1,

17}

19. 4n

2 -

17 =

19 {±

3}

20. x

2 +

30x +

150 =

-75 {-

15}

21. (k

+ 2

)2 =

16 {-

6,

2}

22. (m

- 4

)2 =

7 { 2

± √ %

7 }

8-6

Answers (Lesson 8-6)

Page 19: Answers (Anticipation Guide and Lesson 8-1) © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers Chapter 8 A3 Glencoe Algebra 1 Copyright © Glencoe/McGraw-Hill,

Answers

Co

pyri

gh

t ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f T

he M

cG

raw

-Hill C

om

pan

ies,

Inc.

Chapter 8 A19 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

8

40

Gle

ncoe A

lgeb

ra 1

Practi

ce

Qu

ad

rati

c E

qu

ati

on

s:

Perf

ect

Sq

uare

s

Dete

rm

ine w

heth

er e

ach

trin

om

ial

is a

perfe

ct

sq

ua

re t

rin

om

ial.

Writ

e yes o

r no.

If s

o,

facto

r i

t.

1. m

2 +

16m

+ 6

4

2. 9r2

- 6

r +

1

3. 4

y2 -

20y +

25

y

es;

(m +

8)2

y

es;

(3r -

1)2

y

es;

(2y -

5)2

4. 16p

2 +

24

p +

9

5. 25b

2 -

4b

+ 1

6

6. 49

k2 -

56k

+ 1

6

y

es;

(4p

+ 3

)2

no

y

es;

(7k

- 4

)2

Fa

cto

r e

ach

po

lyn

om

ial,

if

po

ssib

le.

If t

he p

oly

no

mia

l ca

nn

ot

be f

acto

red

, w

rit

e

prim

e.

7. 3

p2 -

147

8. 6x

2 +

11x -

35

9. 50

q2 -

60q

+ 1

8

3

(p +

7)(

p -

7)

(2

x +

7)(

3x -

5)

2(5

q -

3)2

10. 6

t3 -

14

t2 -

12

t 11. 6d

2 -

18

12. 30

k2 +

38k

+ 1

2

2

t(3t +

2)(

t -

3)

6(d

2 -

3)

2(5

k +

3)(

3k

+ 2

)

13. 15b

2 -

24

bf

14. 12h

2 -

60

h +

75

15. 9

n2 -

30

n -

25

3

b(5

b -

8f)

3

(2h

- 5

)2

pri

me

16. 7

u2 -

28m

2

17. w

4 -

8w

2 -

9

18. 16a

2 +

72a

d +

81d

2

7

(u -

2m

)(u

+ 2

m)

(w

2 +

1)(

w +

3)(

w -

3)

(4

a +

9d

)2

So

lve e

ach

eq

ua

tio

n.

Ch

eck

th

e s

olu

tio

ns.

19. 4

k2 -

28k

= -

49

20. 50b

2 +

20

b +

2 =

0

21. ( 1

2 t

- 1

) 2

= 0

{ 7

2 }

{- 1

5 }

{2}

22. g

2 +

2

3 g

+ 1

9 =

0

23. p

2 -

6

5 p

+

9

25 =

0

24. x

2 +

12

x +

36 =

25

{-

1 −

3 }

{ 3 −

5 }

{-

11, -

1}

25. y

2 -

8y +

16 =

64

26. (h

+ 9

)2 =

3

27. w

2 -

6w

+ 9

= 1

3

{-

4,

12}

{-

9 ±

√ $

3 }

{3 ±

√ $$

13 }

28. G

EO

METR

Y T

he a

rea o

f a c

ircl

e i

s giv

en

by t

he f

orm

ula

A =

πr2

, w

here

r i

s th

e r

ad

ius.

If

in

creasi

ng t

he r

ad

ius

of

a c

ircl

e b

y 1

in

ch g

ives

the r

esu

ltin

g c

ircl

e a

n a

rea o

f 100

π

squ

are

in

ches,

wh

at

is t

he r

ad

ius

of

the o

rigin

al

circ

le?

9 i

n.

29. PIC

TU

RE F

RA

MIN

G M

ikaela

pla

ced

a f

ram

e a

rou

nd

a p

rin

t th

at

m

easu

res

10 i

nch

es

by 1

0 i

nch

es.

Th

e a

rea o

f ju

st t

he f

ram

e i

tself

is

69 s

qu

are

in

ches.

Wh

at

is t

he w

idth

of

the f

ram

e?

1.5

in

.1

0

10

x

x

8-6

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Lesson 8-6

Ch

ap

ter

8

41

Gle

ncoe A

lgeb

ra 1

Wo

rd

Pro

ble

m P

racti

ce

Qu

ad

rati

c E

qu

ati

on

s:

Perf

ect

Sq

uare

s

1. C

ON

STR

UC

TIO

N T

he a

rea o

f L

ibert

y

Tow

nsh

ip’s

squ

are

pla

ygro

un

d i

s re

pre

sen

ted

by t

he t

rin

om

ial

x2

- 1

0x

+ 2

5.

Wri

te a

n e

xp

ress

ion

u

sin

g t

he v

ari

able

x t

hat

rep

rese

nts

th

e

peri

mete

r. 4

x-

20 o

r 4(x-

5)

2. A

MU

SEM

EN

T P

AR

KS

F

un

tow

n

Dow

nto

wn

wan

ts t

o b

uil

d a

vert

ical

moti

on

rid

e w

here

th

e p

ass

en

gers

are

la

un

ched

str

aig

ht

up

ward

fro

m g

rou

nd

le

vel

wit

h a

n i

nit

ial

velo

city

of

96 f

eet

per

seco

nd

. T

he r

ide c

ar’

s h

eig

ht

h i

n f

eet

aft

er

t se

con

ds

is h

= 9

6t

- 1

6t2

. H

ow

m

an

y s

eco

nd

s aft

er

lau

nch

wou

ld t

he c

ar

reach

144 f

eet?

3 s

eco

nd

s

3. B

USIN

ESS

S

ain

i S

pri

nk

ler

Com

pan

y

inst

all

s ir

rigati

on

syst

em

s. T

o t

rack

m

on

thly

cost

s C

an

d r

even

ues

R,

they

use

th

e f

oll

ow

ing f

un

ctio

ns,

wh

ere

x i

s th

e n

um

ber

of

syst

em

s th

ey i

nst

all

.

R

(x)

= 8

x2 +

12x

+ 4

C(x

) =

7x

2 +

20x

- 1

2

Th

e m

on

thly

pro

fit

can

be f

ou

nd

by

subtr

act

ing c

ost

fro

m r

even

ue.

P(x

) =

R(x

) -

C(x

)

Fin

d a

fu

nct

ion

to p

roje

ct m

on

thly

pro

fit

an

d u

se i

t to

fin

d t

he b

reak

-even

poin

t w

here

th

e p

rofi

t is

zero

.

P(x

) =

x2-

8x+

16;

x=

4

4. G

EO

METR

YH

oll

y c

an

mak

e a

n o

pen

-to

pp

ed

box o

ut

of

a s

qu

are

pie

ce o

f ca

rdboard

by c

utt

ing 3

-in

ch s

qu

are

s fr

om

th

e c

orn

ers

an

d f

old

ing u

p t

he s

ides

to

meet.

Th

e v

olu

me o

f th

e r

esu

ltin

g b

ox i

s V

=3

x2

-36x

+108,

wh

ere

x i

s th

e

ori

gin

al

len

gth

an

d w

idth

of

the

card

board

.

a.

Fact

or

the p

oly

nom

ial

exp

ress

ion

fro

m

the v

olu

me e

qu

ati

on

. 3(x-

6)(

x-

6)

b

. W

hat

is t

he v

olu

me o

f th

e b

ox i

f th

e

ori

gin

al

len

gth

of

each

sid

e o

f th

e

card

board

was

14 i

nch

es?

192 i

n3

c.

Wh

at

is t

he o

rigin

al

sid

e l

en

gth

of

the

card

board

wh

en

th

e v

olu

me o

f th

e b

ox

is 2

7 i

n3?

9 i

n.

x

x

3 in

3 in

8-6

Answers (Lesson 8-6)

Page 20: Answers (Anticipation Guide and Lesson 8-1) © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers Chapter 8 A3 Glencoe Algebra 1 Copyright © Glencoe/McGraw-Hill,
Page 21: Answers (Anticipation Guide and Lesson 8-1) © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Answers Chapter 8 A3 Glencoe Algebra 1 Copyright © Glencoe/McGraw-Hill,

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