(9m+6)+(-5m-6)
A. 4m+12
B. 14m+12
C. 14m-12
D. 4m
We can simplify this expression by combining like terms:
(9m + 6) + (-5m - 6) = 9m - 5m + 6 - 6
The m terms simplify to 4m, and the 6 and -6 terms cancel each other out. Therefore, we are left with:
4m
So the answer is D. 4m.