C

Step 1: [Original equation.]17y - 7y + 18 = 8y + 24

Step 2: [Combine like terms.]10y + 18 = 8y + 24

Step 3: [Subtract 18 from each side.]10y + 18 - 18 = 8y + 24 - 18

Step 4: [Simplify both sides.]10y = 8y + 6

Step 5: [Subtract 8y from each side.]10y - 8y = 8y + 6 - 8y

Step 6: [Simplify both sides.]2y = 6

Step 7: [Simplify.]y = 3