3, 4, 7, 7的24点答案：1:3 + 4 × 7 - 72:(3 + 4 × 7) - 73:(3 + (4 × 7)) - 74:3 + (4 × 7) - 75:3 + (4 × 7 - 7)6:3 + ((4 × 7) - 7)7:3 - (4 - 7) × 78:3 - ((4 - 7) × 7)9:3 + (7 - 4...