Ali was asked to simplify the expression 3(x - 6) + (4x + 12) - 6x. His work is shown below.


3(x - 6) + (4x + 12) - 6x

3x - 9 + 4x + 12 - 6x

(3x + 4x - 6x) + (-9 + 12)

x + 3