Question

1、2、4、5用加减乘除和括号得数是24,如何运算?

Answer 1

1: (2 - 1 + 5) × 4
2: ((2 - 1) + 5) × 4
3: (2 - (1 - 5)) × 4
4: (2 + 4) × (5 - 1)
5: (2 + 5 - 1) × 4
6: ((2 + 5) - 1) × 4
7: (2 + (5 - 1)) × 4
8: 4 × (2 - 1 + 5)
9: 4 × ((2 - 1) + 5)
10: 4 × (2 - (1 - 5))
11: (4 + 2) × (5 - 1)
12: 4 × (2 + 5 - 1)
13: 4 × ((2 + 5) - 1)
14: 4 × (2 + (5 - 1))
15: 4 × (5 - 1 + 2)
16: 4 × ((5 - 1) + 2)
17: 4 × (5 - (1 - 2))
18: 4 × (5 + 2 - 1)
19: 4 × ((5 + 2) - 1)
20: 4 × (5 + (2 - 1))
21: (5 - 1 + 2) × 4
22: ((5 - 1) + 2) × 4
23: (5 - (1 - 2)) × 4
24: (5 - 1) × (2 + 4)
25: (5 - 1) × (4 + 2)
26: (5 + 2 - 1) × 4
27: ((5 + 2) - 1) × 4
28: (5 + (2 - 1)) × 4

Answer 2

http://www.dffy.com/tool/24.htm
这个是电脑帮 你算24点
1: (2 - 1 + 5) × 4
2: ((2 - 1) + 5) × 4
3: (2 - (1 - 5)) × 4
4: (2 + 4) × (5 - 1)
5: (2 + 5 - 1) × 4
6: ((2 + 5) - 1) × 4
7: (2 + (5 - 1)) × 4
8: 4 × (2 - 1 + 5)
9: 4 × ((2 - 1) + 5)
10: 4 × (2 - (1 - 5))
11: (4 + 2) × (5 - 1)
12: 4 × (2 + 5 - 1)
13: 4 × ((2 + 5) - 1)
14: 4 × (2 + (5 - 1))
15: 4 × (5 - 1 + 2)
16: 4 × ((5 - 1) + 2)
17: 4 × (5 - (1 - 2))
18: 4 × (5 + 2 - 1)
19: 4 × ((5 + 2) - 1)
20: 4 × (5 + (2 - 1))
21: (5 - 1 + 2) × 4
22: ((5 - 1) + 2) × 4
23: (5 - (1 - 2)) × 4
24: (5 - 1) × (2 + 4)
25: (5 - 1) × (4 + 2)
26: (5 + 2 - 1) × 4
27: ((5 + 2) - 1) × 4
28: (5 + (2 - 1)) × 4