−15x−40=23−8x
What does x =

x = -9

Step-by-step explanation:

-15x - 40 = 23 - 8x  

Add 8x to both sides

-15x + 8x - 40 = 23

          -7x - 40 = 23

Add 40 to both sides

                - 7x = 23 + 40

                  -7x = 63

 Divide both sides by (-7)

            x = 63/-7

x = -9

109 is the nearest whole number/final answer! : )

c.

step-by-step explanation:

she should of added 9^2 and 12^2. that is because it is a^2+b^2=c^2. c^2 is the hypotenuse and should always be bigger than the other two numbers. which is why she should of added 9 squared and 12 squared together instead of 15 squared.