Which expression is equivalent to 6 (2m - 1) - 4 (m + 8) ?

If these are the choices:

A. 8m - 38

B. 8m + 7

C. 8m + 31

D. 2m - 38

Solution:

6 (2m - 1) - 4 (m + 8)

distributive property of multiplication:

6 (2m) + 6 (-1) - 4 (m) - 4 (8)

12m - 6 - 4m - 32

combine like terms:

12m - 4m - 6 - 32

8m - 38 choice A.