| 3 | x | − | 2 | ( | x | + | 3 | ) | = | 4 | ( | x | − | 1 | ) | + | 7 |
| 方程左边 = | 3 | x | − | 2 | x | − | 2 | × | 3 |
| = | 3 | x | − | 2 | x | − | 6 |
| = | 1 | x | − | 6 |
| 1 | x | − | 6 | = | 4 | ( | x | − | 1 | ) | + | 7 |
| 方程右边 = | 4 | x | − | 4 | × | 1 | + | 7 |
| = | 4 | x | − | 4 | + | 7 |
| = | 4 | x | + | 3 |
| 1 | x | − | 6 | = | 4 | x | + | 3 |
| 1 | x | − | 4 | x | = | 3 | + | 6 |
| - | 3 | x | = | 3 | + | 6 |
| - | 3 | x | = | 9 |
| - | 9 | = | 3 | x |
| 3 | x | = | - | 9 |
| x | = | - | 9 | ÷ | 3 |
| = | - | 9 | × | 1 3 |
| = | - | 3 | × | 1 |
| x | = | - | 3 |