We have the following equation:
-3m + 2 (2 + 2m) = -1
-3m + 4 + 4m = -1
Like terms:
-3m + 4m = -1 - 4
m = -5
Let's prove our answer replacing m by -5 on the original equation , this way:
-3 * - 5 + 2 (2 + 2 * -5) = -1
15 + 2 (2 -10) = -1
15 + 2 * -8 = -1
15 - 16 = -1
-1 = -1
Our answer is correct