4 9 9 12如何等于24
2个回答

1: 4 × (9 + 9 - 12)

2: 4 × ((9 + 9) - 12)

3: 4 × (9 + (9 - 12))

4: 4 × (9 - 12 + 9)

5: 4 × ((9 - 12) + 9)

6: 4 × (9 - (12 - 9))

7: (4 - 12 ÷ 9) × 9

8: (4 - (12 ÷ 9)) × 9

9: 9 × (4 - 12 ÷ 9)

10: 9 × (4 - (12 ÷ 9))

11: (9 + 9 - 12) × 4

12: ((9 + 9) - 12) × 4

13: (9 + (9 - 12)) × 4

14: (9 - 12 + 9) × 4

15: ((9 - 12) + 9) × 4

16: (9 - (12 - 9)) × 4