| 序号 | 题目:8,9,11,12 | |
|---|---|---|
| 1 | ((11 + 9) + 12) − 8 | |
| 2 | ((12 + 9) + 11) − 8 | |
| 3 | ((12 + 11) − 8) + 9 | |
| 4 | ((12 + 9) − 8) + 11 | |
| 5 | ((12 + 11) + 9) − 8 | |
| 6 | (12 + 11) + (9 − 8) | |
| 7 | (12 + 9) + (11 − 8) | |
| 8 | (9 + (12 − 8)) + 11 | |
| 9 | (11 + (12 − 8)) + 9 | |
| 10 | (12 + (11 − 8)) + 9 | |
| 11 | (11 + 9) + (12 − 8) | |
| 12 | (12 + (9 − 8)) + 11 | |
| 13 | 12 + (11 + (9 − 8)) | |
| 14 | 12 + ((11 + 9) − 8) | |
| 15 | 12 + (9 + (11 − 8)) | |