-9h - 6 + 12h + 40 = 22. Combine on the left to simplify
12h-9h +40-6 = 22
3h +34 = 22 We need the part with the unknown on one side and the plain numbers on the other side. Since 34 is being added on the left, we must do the opposite thing. Subtract 34 from both sides.
Then we need the unknown to stand alone. Since h is being multiplied by 3, we must do the opposite thing. Divide both sides by 3.