Respuesta :

KassandraVillegas
The ore the answer is B. Why?

Because (-4m+1) + (7m-9) = 3m - 8

You add -4m and 7m and get 3m and the only answer that has a POSITIVE 3m is B.

Anyways, you still have to check it. 1+(-9) is -8. So A+B = 3m - 8
znk

Answer:

b. 3m - 8

Step-by-step explanation:

    A = -4m + 1

    B =   7m -  9     Add the terms in columns

A +B =  3m -  8