| 2 | x | − | 4 | ( | x | + | 1 | ) | = | 5 | ( | x | + | 1 | ) | − | 6 |
| 方程左边 = | 2 | x | − | 4 | x | − | 4 | × | 1 |
| = | 2 | x | − | 4 | x | − | 4 |
| = | - | 2 | x | − | 4 |
| - | 2 | x | − | 4 | = | 5 | ( | x | + | 1 | ) | − | 6 |
| 方程右边 = | 5 | x | + | 5 | × | 1 | − | 6 |
| = | 5 | x | + | 5 | − | 6 |
| = | 5 | x | − | 1 |
| - | 2 | x | − | 4 | = | 5 | x | − | 1 |
| - | 2 | x | − | 5 | x | = | - | 1 | + | 4 |
| - | 7 | x | = | - | 1 | + | 4 |
| - | 7 | x | = | 3 |
| - | 3 | = | 7 | x |
| 7 | x | = | - | 3 |
| x | = | - | 3 | ÷ | 7 |
| = | - | 3 | × | 1 7 |
| x | = | - | 3 7 |
| x | = | - 0.428571 |