Simplify -5x + 12 - 7x to -12x + 12
-12x + 12 = -3(5x + 8)
Expand
-12x + 12 = -15x - 24
Add 15x to both sides
-12x + 12 + 15x = -24
Simplify 12x + 12 + 15x to 3x + 12
3x + 12 = -24
Subtract 12 from both sides
3x = -24 - 12
Simplify -24 - 12 to -36
3x = -36
Divide both sides by 3
x = -36/3
Simplify 36/3 to 12
x = -12
