| 7 | ( | - | 6 | x | − | 2 | ) | − | 13 | ( | x | − | 2 | ) | − | 7 | = | 5 |
| 方程左边 = | - | 7 | × | 6 | x | − | 7 | × | 2 | − | 13 | ( | x | − | 2 | ) | − | 7 |
| = | - | 42 | x | − | 14 | − | 13 | ( | x | − | 2 | ) | − | 7 |
| = | - | 42 | x | − | 21 | − | 13 | ( | x | − | 2 | ) |
| = | - | 42 | x | − | 21 | − | 13 | x | + | 13 | × | 2 |
| = | - | 42 | x | − | 21 | − | 13 | x | + | 26 |
| = | - | 55 | x | + | 5 |
| - | 55 | x | + | 5 | = | 5 |
| - | 55 | x | = | 5 | − | 5 |
| - | 55 | x | = | 0 |
| - | 0 | = | 55 | x |
| 55 | x | = | - | 0 |
| x | = | - | 0 | ÷ | 55 |
| = | - | 0 | × | 1 55 |
| x | = | 0 |