His mistake was adding the +2 on the other side instead of -2. When you move any number from one side to the equal sign to the other, the sign of it switches. He also forget to divide both sides by 3 to isolate the x variable.
correct answer:
3x + 2 = 35
3x = 35 -2
3x = 33
3x 33
—— = ——
3 3
x = 11
