| - | 10 | + | 7 | ( | 9 | − | 3 | ( | - | 17 | + | x | ) | ) | = | 2 | ( | 6 | x | + | 7 | ) |
| 方程左边 = | - | 10 | + | 7 | × | 9 | − | 7 | × | 3 | ( | - | 17 | + | x | ) |
| = | - | 10 | + | 63 | − | 21 | ( | - | 17 | + | x | ) |
| = | 53 | − | 21 | ( | - | 17 | + | x | ) |
| = | 53 | + | 21 | × | 17 | − | 21 | x |
| = | 53 | + | 357 | − | 21 | x |
| = | 410 | − | 21 | x |
| 410 | − | 21 | x | = | 2 | ( | 6 | x | + | 7 | ) |
| 方程右边 = | 2 | × | 6 | x | + | 2 | × | 7 |
| = | 12 | x | + | 14 |
| 410 | − | 21 | x | = | 12 | x | + | 14 |
| - | 21 | x | − | 12 | x | = | 14 | − | 410 |
| - | 33 | x | = | 14 | − | 410 |
| - | 33 | x | = | - | 396 |
| 396 | = | 33 | x |
| 33 | x | = | 396 |
| x | = | 396 | ÷ | 33 |
| = | 396 | × | 1 33 |
| = | 12 | × | 1 |
| x | = | 12 |