8. Simplify and solve this equation: 4m + 9 + 5m - 12 = 42. A. m = 5 B. m = - 5 C. m = 4 D. m = - 4

4m+9+5m-12=42 9m-3=42 Divide bothsides by 9. 9m/9 - 3/9=-0.3=-4 m=-4

4m+9+5m-12=42

Combine 9 and - 12 and you get - 3 so

4m+5m-3=42

And then combine 4m and 5m and you get 9m so

9m-3=42

And then add three on both sides (canceling out the - 3) leaving you with

9m=45

And then divide 45 by 9 and you get 5 so

m=5.

The answer is A. M=5