由9 7 5 4组成的24点等式全部如下,
1:4 × 7 + 5 - 9
2:(4 × 7) + 5 - 9
3:(4 × 7 + 5) - 9
4:((4 × 7) + 5) - 9
5:4 × 7 +(5 - 9)
6:(4 × 7) + (5 - 9)
7:4 × 7 - 9 + 5
8:(4 × 7) - 9 + 5
9:(4 × 7 - 9) + 5
10:((4 × 7) - 9) + 5
11:4 × 7 -(9 - 5)
12:(4 × 7) - (9 - 5)
13:4 × 9 -(5 + 7)
14:(4 × 9) - (5 + 7)
15:4 × 9 - 5 - 7
16:(4 × 9) - 5 - 7
17:(4 × 9 - 5) - 7
18:((4 × 9) - 5) - 7
19:4 × 9 -(7 + 5)
20:(4 × 9) - (7 + 5)
21:4 × 9 - 7 - 5
22:(4 × 9) - 7 - 5
23:(4 × 9 - 7) - 5
24:((4 × 9) - 7) - 5
25:5 + 4 × 7 - 9
26:(5 + 4 × 7) - 9
27:(5 + (4 × 7)) - 9
28:5 + (4 × 7) - 9
29:5 + (4 × 7 - 9)
30:5 + ((4 × 7) - 9)
31:5 + 7 × 4 - 9
32:(5 + 7 × 4) - 9
33:(5 + (7 × 4)) - 9
34:5 + (7 × 4) - 9
35:5 + (7 × 4 - 9)
36:5 + ((7 × 4) - 9)
37:(5 × (7 - 4)) + 9
38:5 × (7 - 4) + 9
39:5 - 9 + 4 × 7
40:(5 - 9) + 4 × 7
41:5 - 9 +(4 × 7)
42:(5 - 9) + (4 × 7)
43:5 - (9 - 4 × 7)
44:5 - (9 - (4 × 7))
45:5 - 9 + 7 × 4
46:(5 - 9) + 7 × 4
47:5 - 9 +(7 × 4)
48:(5 - 9) + (7 × 4)
49:5 - (9 - 7 × 4)
50:5 - (9 - (7 × 4))
51:(7 - 4) × 5 + 9
52:((7 - 4) × 5) + 9
53:7 × 4 + 5 - 9
54:(7 × 4) + 5 - 9
55:(7 × 4 + 5) - 9
56:((7 × 4) + 5) - 9
57:7 × 4 +(5 - 9)
58:(7 × 4) + (5 - 9)
59:7 × 4 - 9 + 5
60:(7 × 4) - 9 + 5
61:(7 × 4 - 9) + 5
62:((7 × 4) - 9) + 5
63:7 × 4 -(9 - 5)
64:(7 × 4) - (9 - 5)
65:(7 × (9 - 5)) - 4
66:7 × (9 - 5) - 4
67:9 × 4 -(5 + 7)
68:(9 × 4) - (5 + 7)
69:9 × 4 - 5 - 7
70:(9 × 4) - 5 - 7
71:(9 × 4 - 5) - 7
72:((9 × 4) - 5) - 7
73:9 - (4 - 7) × 5
74:9 - ((4 - 7) × 5)
75:9 × 4 -(7 + 5)
76:(9 × 4) - (7 + 5)
77:9 × 4 - 7 - 5
78:(9 × 4) - 7 - 5
79:(9 × 4 - 7) - 5
80:((9 × 4) - 7) - 5
81:9 - (5 × (4 - 7))
82:9 - 5 ×(4 - 7)
83:9 + (5 × (7 - 4))
84:9 + 5 ×(7 - 4)
85:(9 - 5) × 7 - 4
86:((9 - 5) × 7) - 4
87:9 + (7 - 4) × 5
88:9 + ((7 - 4) × 5)
你给的顺序无解