Solving a two-step equation

Steps

8-3y=14

reasons

• Original equation

• 8-3y-8=14-8

• -3y=6

• y= -2

• simplify

• Subtraction property of equality

• Division property of equality

• simplify

Put the reasons in the right order

Solving a two step equation

Steps

12-2a=8

reasons

• Original equation

• 12-2a-12=8-12

• -2a=-4

• a= 2

• simplify

• Subtraction property of equality

• Division property of equality

• simplify

Put the steps in the right order

Solving a two step equation

Steps

-x-5=11

reasons

• -x=16

• x=-16

• -x-5+5=11+5

Justify each step

Find the error?Steps

12-3y= 15

reasons

• Original equation

• 12-3y-12=15-12

• 3y=3

• y= 1

• simplify

• Subtraction property of equality

• Division property of equality

• simplify

Find the error?Steps reasons

• Original equation

• m= -4

• simplify

• Subtraction property of equality

• Multiplication property of equality

• simplify

Depth of a coal mine in kilometer d

Beneath Earth’s surface, the temperature increases 10˚C every kilometer. Suppose that the surface temperature is 22˚C, and the temperature at the bottom of a coal mine is 45˚C. Which equation could be used to find the depth d of the coal mine?

Temperature increases at d kilometer

Temperature at the bottom of a coal mine

The surface temperature

10d

22

45

Surface tempe-rature

timesplus

Tempe-rature increase

Beneath Earth’s surface, the temperature increases 10˚C every kilometer. Suppose that the surface temperature is 22˚C, and the temperature at the bottom of a coal mine is 45˚C. Which equation could be used to find the depth d of the coal mine?

number of kilome-ters

equals

the depth of the coal mine

Put at the write position:

d45

2210

+

=

*

Now solve the equation!

Time for fun

Thank you!