3, 7, 9, 3的24点答案：
1: 3 + 7 × 9 ÷ 3
2: 3 + (7 × 9) ÷ 3
3: 3 + (7 × 9 ÷ 3)
4: 3 + ((7 × 9) ÷ 3)
5: 3 + (7 × (9 ÷ 3))
6: 3 + 7 ×(9 ÷ 3)
7: 3 × 7 + 9 ÷ 3
8: (3 × 7) + 9 ÷ 3
9: 3 × 7 +(9 ÷ 3)
10: (3 × 7) + (9 ÷ 3)
11: 3 + 7 ÷ 3 × 9
12: 3 + (7 ÷ 3) × 9
13: 3 + (7 ÷ 3 × 9)
14: 3 + ((7 ÷ 3) × 9)
15: 3 + (7 ÷ (3 ÷ 9))
16: 3 + 7 ÷(3 ÷ 9)
17: (3 - 7) × (3 - 9)
18: 3 + 9 × 7 ÷ 3
19: 3 + (9 × 7) ÷ 3
20: 3 + (9 × 7 ÷ 3)
21: 3 + ((9 × 7) ÷ 3)
22: 3 + (9 × (7 ÷ 3))
23: 3 + 9 ×(7 ÷ 3)
24: 3 + 9 ÷ 3 × 7
25: 3 + (9 ÷ 3) × 7
26: 3 + (9 ÷ 3 × 7)
27: 3 + ((9 ÷ 3) × 7)
28: 3 + (9 ÷ (3 ÷ 7))
29: 3 + 9 ÷(3 ÷ 7)
30: (3 - 9) × (3 - 7)
31: (7 - 3) × (9 - 3)
32: 7 × 3 + 9 ÷ 3
33: (7 × 3) + 9 ÷ 3
34: 7 × 3 +(9 ÷ 3)
35: (7 × 3) + (9 ÷ 3)
36: 7 ÷ 3 × 9 + 3
37: (7 ÷ 3) × 9 + 3
38: (7 ÷ 3 × 9) + 3
39: ((7 ÷ 3) × 9) + 3
40: (7 ÷ (3 ÷ 9)) + 3
41: 7 ÷ (3 ÷ 9) + 3
42: 7 × 9 ÷ 3 + 3
43: (7 × 9) ÷ 3 + 3
44: (7 × 9 ÷ 3) + 3
45: ((7 × 9) ÷ 3) + 3
46: (7 × (9 ÷ 3)) + 3
47: 7 × (9 ÷ 3) + 3
48: (9 - 3) × (7 - 3)
49: 9 ÷ 3 + 7 × 3
50: (9 ÷ 3) + 7 × 3
51: 9 ÷ 3 +(7 × 3)
52: (9 ÷ 3) + (7 × 3)
53: 9 ÷ 3 × 7 + 3
54: (9 ÷ 3) × 7 + 3
55: (9 ÷ 3 × 7) + 3
56: ((9 ÷ 3) × 7) + 3
57: (9 ÷ (3 ÷ 7)) + 3
58: 9 ÷ (3 ÷ 7) + 3
59: 9 ÷ 3 + 3 × 7
60: (9 ÷ 3) + 3 × 7
61: 9 ÷ 3 +(3 × 7)
62: (9 ÷ 3) + (3 × 7)
63: 9 × 7 ÷ 3 + 3
64: (9 × 7) ÷ 3 + 3
65: (9 × 7 ÷ 3) + 3
66: ((9 × 7) ÷ 3) + 3
67: (9 × (7 ÷ 3)) + 3
68: 9 × (7 ÷ 3) + 3
参考资料：57: (9 ÷ (3 ÷ 7)) + 3