37 = -3 + 5(x + 6)
Distributing:
37 = -3 + 5(x) + 5(6)
37 = -3 + 5x + 30
Commuting:
37 = -3 + 30 + 5x
37 = 27 + 5x
27 is adding on the right, then it will subtract on the left.
37 - 27 = 5x
10 = 5x
5 is multiplying on the right, then it will divide on the left
10/5 = x
2 = x