First off, you don't need the parentheses. It's all being added so they aren't necessary.
x + 6 + x + 3x - 16 = 180
Add like terms on each side
(I rearranged them so it would make more sense and be easier to see— this doesn't change anything about the equation, since it's only addition and the order doesn't matter. This is called the commutative property.)
x + x + 3x + 6 - 16 = 180
5x - 10 = 180
5x = 190
x = 38
I hope that helps
