Explanation:
-3(x-10)/4 + 2 = 11
-3(x-10)/4 = 9
-3(x-10) = 36
-3x + 30 = 36
-3x = 6
x = 6/-3 = -2
piece by piece transform such an equation.
eliminate 1 element at a time, combine terms, calculate bracket expressions, ... so that you get to a form, where the variable is in one side, and the rest on the other side.
always remember, to keep the equation true, whatever we do on side, we also have to do on the other side every time.