Question

3-2(m+4)=15 how do I do this

Answer 1

    3 - 2(m + 4) = 15
3 - 2(m) - 2(4) = 15
       3 - 2m - 8 = 15
       3 - 8 - 2m = 15
           -5 - 2m = 15
         + 5           + 5
                -2m = 20
                  -2     -2
                   m = -10

Answer 2

Multipy -2(m+4) first
Then you have
3-2m-8=15
Subtact 3 and 8 from each side
-2m=4
Divide by -2 on both sides
m=-2
Then plug in -2 for m to check