Take into account that:
m
then, replace the given expressions into th previous equation:
180 = (2x + 6) + (3x + 2) cancel parenthesis
180 = 2x + 6 + 3x + 2 simplify like terms right side
180 = 2x + 3x + 6 + 2
180 = 5x + 8 subtract 8 both sides
180 - 8 = 5x simplify like terms left side
172 = 5x divide by 5 both sides
172/5 = x
34.4 = x