| - | 8 | − | ( | 18 | + | 5 | ( | 2 | + | 9 | x | ) | ) | = | 6 | ( | - | 6 | x | + | 9 | ) |
| 方程左边 = | - | 8 | − | 18 | − | 5 | ( | 2 | + | 9 | x | ) |
| = | - | 26 | − | 5 | ( | 2 | + | 9 | x | ) |
| = | - | 26 | − | 5 | × | 2 | − | 5 | × | 9 | x |
| = | - | 26 | − | 10 | − | 45 | x |
| = | - | 36 | − | 45 | x |
| - | 36 | − | 45 | x | = | 6 | ( | - | 6 | x | + | 9 | ) |
| 方程右边 = | - | 6 | × | 6 | x | + | 6 | × | 9 |
| = | - | 36 | x | + | 54 |
| - | 36 | − | 45 | x | = | - | 36 | x | + | 54 |
| - | 45 | x | + | 36 | x | = | 54 | + | 36 |
| - | 9 | x | = | 54 | + | 36 |
| - | 9 | x | = | 90 |
| - | 90 | = | 9 | x |
| 9 | x | = | - | 90 |
| x | = | - | 90 | ÷ | 9 |
| = | - | 90 | × | 1 9 |
| = | - | 10 | × | 1 |
| x | = | - | 10 |