| X | + | ( | X | − | 2 | ) | = | 2 | ( | X | − | 6 | ) | + | ( | X | − | 4 | ) |
| 方程左边 = | X | + | X | − | 2 |
| = | 2 | X | − | 2 |
| 2 | X | − | 2 | = | 2 | ( | X | − | 6 | ) | + | ( | X | − | 4 | ) |
| 方程右边 = | 2 | X | − | 2 | × | 6 | + | ( | X | − | 4 | ) |
| = | 2 | X | − | 12 | + | ( | X | − | 4 | ) |
| = | 2 | X | − | 12 | + | X | − | 4 |
| = | 3 | X | − | 16 |
| 2 | X | − | 2 | = | 3 | X | − | 16 |
| 2 | X | − | 3 | X | = | - | 16 | + | 2 |
| - | X | = | - | 16 | + | 2 |
| - | X | = | - | 16 | + | 2 |
| - | X | = | - | 14 |
| 14 | = | X |
| X | = | 14 |