Distribute into the parenthesis and you get: -3y+15=24. Now, subtract 15 on both sides and you will get: -3y = 9. Finally, divide -3 on both sides and you will get the final answer: y = -3. You can check your answer by substituting -3 into the original equation: -3(-3-5) = 24. 9 + 15 = 24. 24 = 24