The sum of a number and -9 is-36?

Question

Can u plss help me solve this?

Answer 1

Call the unknown number 'x'. The sum of the number and -9 is x+(-9) or just x-9

You know that it is equal to -36, so x-9=-36

Add 9 to both sides to get x by itself, so (x-9)+9 = -36 + 9

Combine like terms to get x=-27