Respuesta :

1. Simplify -9 + -2m to -9 - 2m

-3m = -9 - 2m

2. 
Add 2m to both sides

-3m + 2m = -9

3. 
Simplify -3m + 2m to -m

-m = -9

4. 
Multiply both sides by 1

m = 9

Done! :) our answer is m = 9