7，2，-5，-13 如何算出24点

(-5+7)*(-13)-2=24

(-5+7)*(-13)-2=24

上面的不对，没有5。
2-13-（-5*7）＝24

: 2 - 13 + (-5)×(- 7)
2: (2 - 13) + (-5)×(- 7)

3: 2 - 13 +(-5)×(- 7)

4: (2 - 13) + (-5)×(- 7)

5: 2 - (13 - (-5)×(- 7)

7: 2 × 13 + 5 - 7
8: (2 × 13) + 5 - 7
9: (2 × 13 + 5) - 7
10: ((2 × 13) + 5) - 7
11: 2 × 13 +(5 - 7)
12: (2 × 13) + (5 - 7)
13: 2 - 13 + 7 × 5
14: (2 - 13) + 7 × 5
15: 2 - 13 +(7 × 5)
16: (2 - 13) + (7 × 5)
17: 2 - (13 - 7 × 5)
18: 2 - (13 - (7 × 5))
19: 2 × 13 - 7 + 5
20: (2 × 13) - 7 + 5
21: (2 × 13 - 7) + 5
22: ((2 × 13) - 7) + 5
23: 2 × 13 -(7 - 5)
24: (2 × 13) - (7 - 5)
25: 2 + 5 × 7 - 13
26: (2 + 5 × 7) - 13
27: (2 + (5 × 7)) - 13
28: 2 + (5 × 7) - 13
29: 2 + (5 × 7 - 13)
30: 2 + ((5 × 7) - 13)
31: 2 + 7 × 5 - 13
32: (2 + 7 × 5) - 13
33: (2 + (7 × 5)) - 13
34: 2 +