MULTIPLYING POLYNOMIALS:FOILLesson 10-3

MULTIPLYING POLYNOMIALS

When multiplying two BINOMIALS…

…we multiply by “FOIL”First termsOuter termsInner termsLast terms

MULTIPLYING POLYNOMIALS

(2x + 1) (x – 5)

FOIL = distribution, combine like terms

2x – 10x + 1x -5

2x – 9x -5

MULTIPLYING POLYNOMIALS

(3x – 5) (2x + 7)

6x² + 21x – 10x – 35

6x² + 11x – 35

(x – 7) (3x + 1)

3x² + x – 21x – 7

3x² – 20x - 7

MULTIPLYING POLYNOMIALS

Special products:(x – 5) (x + 5)

x² + 5x – 5x – 25

x² – 25

Special products:(2x – 8) (2x +

8)

4x² + 16x – 16x – 64

4x² – 64

MULTIPLYING POLYNOMIALS

When multiplying a trinomial & binomial…… distribution and combine like terms

(3x² + x – 6) (2x – 3) (2x – 3) (3x² + x – 6)

6x³ + 2x² – 12x - 9x² - 3x + 18

6x³ - 7x² – 15x + 18

MULTIPLYING POLYNOMIALS

Find the product:

(3a + 4) (5a² + 2a – 3)

15a³ + 6a² - 9a + 20a² + 8a – 12

15a³ + 26a² - a - 12

PRACTICE

a) (x + 2) (x + 5)

b) (2x – 1) (x + 2)

c) (a – 6) (a + 6)

d) (f² - 3f) (f² + 6f – 4)

HOMEWORK

p. 478-479 #14-19, 23-29, 41-43