7m+3(m+2)=-24
Distribute
3(m+2)=3m+6
7m+3m+6=-24
Combine like terms
7m+3m=10m
10m+6=24
Do the additive inverse of addition
-24-6=
Do keep change change
-24+-6=-30
10m=-30
Do the inverse of division/multiplication
the m cancels out
-30÷10=-3
because a negative divided by a positive equals a negative the result is -3
this is why it is -3.