M + 9 = - 12

what do you do first

You subtract 9 from both sides

Step-by-step explanation:

You have to get the variable by itself to solve so you subract 9 by 9 and they cancel each other out. Then you do - 12-9 and since they are both negative you get get - 21

Them you have your answer m=-21, you can check this by plugging m inot the equation

If you are solving for M

You would subtract 9

m + 9 = - 12

- 9 - 9

M = - 21