4,1,-3,7的24点答案：1:4 - (1 - 3 × 7)2:4 × 7 - 1 - 33:(4 × 7) - 1 - 34:(4 × 7 - 1) - 35:((4 × 7) - 1) - 36:4 × 7 - 3 - 17:(4 × 7) - 3 - 18:(4 × 7 - 3) - 19:((4 × 7) - 3) - 110:7 × 4 - 1 - 31...