4，7，7，8怎么算得 24

1: (4 - 7 ÷ 7) × 8
2: (4 - (7 ÷ 7)) × 8
3: 4 × (7 + 7 - 8)
4: 4 × ((7 + 7) - 8)
5: 4 × (7 + (7 - 8))
6: 4 × (7 - 8 + 7)
7: 4 × ((7 - 8) + 7)
8: 4 × (7 - (8 - 7))
9: (7 + 7 - 8) × 4
10: ((7 + 7) - 8) × 4
11: (7 + (7 - 8)) × 4
12: (7 - 8 + 7) × 4
13: ((7 - 8) + 7) × 4
14: (7 - (8 - 7)) × 4
15: 8 × (4 - 7 ÷ 7)
16: 8 × (4 - (7 ÷ 7))

8 × (4 - 7 ÷ 7)
4 × (7 + (7 - 8)
4 × (7 + 7 - 8)
(7 - 8 + 7) × 4

上网搜的,有啥可厉害的

楼上的厉害!