Question

Solve the linear equation using any technique you have learned. Name the technique. Check.

3x + 12 = -7x - 28
I know the answer is x = -4
and I know that substitution is the technique that is used, but I can't figure out how to set this up

Answer 1

3(-4) + 12 = -7(-4) - 28

-12 + 12 = 28 - 28

0 = 0

Answer 2

3x + 12 = -7x - 28
Add 7x to both sides
3x + 12 + 7x = -7x - 28 + 7x
10x + 12 = -28
Now subtract 12 from both sides
10x + 12 - 12 = -28 - 12
10x = -40
now divide both terms by 10
x = -4