Question

Here is an equation 2x + 9 = -15. Write three different equations that have the same solution as 2x + 9 = -15. Show or explain how you found them.

Answer 1

Answer:

.5(4x+18)=-15   Half of 4 is 2 and half of 18 is nine

-15-9=2x   Basically just flip the problem

2x+15=-9   Rearrange them again...

Answer 2

To find those equations we can do any multiplication or division of both sides of the equation:

Examples:

2x + 9 = -15              | · 2

4x + 18 = -30

2x + 9 = -15              | · (-1)

-2x - 9 = 15

2x + 9 = -15               | ÷ 2

x + 4.5 = -7.5

There is the same solution: x = -12.