24点游戏（1 4 2 6）不可调换顺序，怎么组合

1: (4 - 1) × (2 + 6)

2: (4 - 1) × (6 + 2)

3: (4 × (2 - 1)) × 6

4: 4 × (2 - 1) × 6

5: 4 × ((2 - 1) × 6)

6: (4 ÷ (2 - 1)) × 6

7: 4 ÷ (2 - 1) × 6

8: 4 ÷ ((2 - 1) ÷ 6)

9: 4 × (6 × (2 - 1))

10: 4 × 6 ×(2 - 1)

11: (4 × 6) × (2 - 1)

12: 4 × (6 ÷ (2 - 1))

13: 4 × 6 ÷(2 - 1)

14: (4 × 6) ÷ (2 - 1)

15: (2 - 1) × 4 × 6

16: ((2 - 1) × 4) × 6

17: (2 - 1) × (4 × 6)

18: (2 - 1) × 6 × 4

19: ((2 - 1) × 6) × 4

20: (2 - 1) × (6 × 4)

21: (2 + 6) × (4 - 1)

22: 6 × (4 × (2 - 1))

23: 6 × 4 ×(2 - 1)

24: (6 × 4) × (2 - 1)

25: 6 × (4 ÷ (2 - 1))

26: 6 × 4 ÷(2 - 1)

27: (6 × 4) ÷ (2 - 1)

28: (6 × (2 - 1)) × 4

29: 6 × (2 - 1) × 4

30: 6 × ((2 - 1) × 4)

31: (6 ÷ (2 - 1)) × 4

32: 6 ÷ (2 - 1) × 4

33: 6 ÷ ((2 - 1) ÷ 4)

34: (6 + 2) × (4 - 1)

必须改变顺序！