Question

Solve the equation. x+7=−8

Answer 1

X+7=-8
You are trying to get x on its own so you will subtract 7 from both sides. 
x+7-7=-8-7
This simplifies to x= -8-7
A negative plus a negative equals a negative. So -8-7 equals -15
Your final answer is x=-15

Answer 2

Solution 

1) Subtract 7 from each side
x=−8−7

2) Simplify −8−7 to −15
x=−15