| 1 | − | 2 | ( | x | − | 5 | ) | = | 3 | ( | 3 | − | 3 | x | ) |
| 方程左边 = | 1 | − | 2 | x | + | 2 | × | 5 |
| = | 1 | − | 2 | x | + | 10 |
| = | 11 | − | 2 | x |
| 11 | − | 2 | x | = | 3 | ( | 3 | − | 3 | x | ) |
| 方程右边 = | 3 | × | 3 | − | 3 | × | 3 | x |
| = | 9 | − | 9 | x |
| 11 | − | 2 | x | = | 9 | − | 9 | x |
| - | 2 | x | + | 9 | x | = | 9 | − | 11 |
| 7 | x | = | 9 | − | 11 |
| 7 | x | = | - | 2 |
| x | = | - | 2 | ÷ | 7 |
| = | - | 2 | × | 1 7 |
| x | = | - | 2 7 |
| x | = | - 0.285714 |