Answer :
Well, you have already said that X is equal to -12 so, we can still check your answer using substitution.
X = -12
2(X + 4) = 4x + 16
2((-2) + 4) = 4(-2) + 16
2(2) = -8 + 16
4 = 8
X = -12
2(X + 4) = 4x + 16
2((-2) + 4) = 4(-2) + 16
2(2) = -8 + 16
4 = 8