3,7,7,7算24点

（7÷7+7）×3

1: 3 + 7 + 7 + 7
2: (3 + 7) + 7 + 7
3: (3 + 7 + 7) + 7
4: ((3 + 7) + 7) + 7
5: (3 + (7 + 7)) + 7
6: 3 + (7 + 7) + 7
7: 3 + (7 + 7 + 7)
8: 3 + ((7 + 7) + 7)
9: 3 + (7 + (7 + 7))
10: 3 + 7 +(7 + 7)
11: (3 + 7) + (7 + 7)
12: 3 × (7 + 7 ÷ 7)
13: 3 × (7 + (7 ÷ 7))
14: 3 × (7 ÷ 7 + 7)
15: 3 × ((7 ÷ 7) + 7)
16: 7 + 3 + 7 + 7
17: (7 + 3) + 7 + 7
18: (7 + 3 + 7) + 7
19: ((7 + 3) + 7) + 7
20: (7 + (3 + 7)) + 7
21: 7 + (3 + 7) + 7
22: 7 + (3 + 7 + 7)
23: 7 + ((3 + 7) + 7)
24: 7 + (3 + (7 + 7))
25: 7 + 3 +(7 + 7)
26: (7 + 3) + (7 + 7)
27: 7 + 7 + 3 + 7
28: (7 + 7) + 3 + 7
29: (7 + 7 + 3) + 7
30: ((7 + 7) + 3) + 7
31: (7 + (7 + 3)) + 7
32: 7 + (7 + 3) + 7
33: 7 + (7 + 3 + 7)
34: 7 + ((7 + 3) + 7)
35: 7 + (7 + (3 + 7))
36: 7 + 7 +(3 + 7)
37: (7 + 7) + (3 + 7)
38: