| 2 | ( | 4 | x | − | 7 | ) | − | 5 | ( | 2 | x | − | 1 | ) | = | 7 |
| 方程左边 = | 2 | × | 4 | x | − | 2 | × | 7 | − | 5 | ( | 2 | x | − | 1 | ) |
| = | 8 | x | − | 14 | − | 5 | ( | 2 | x | − | 1 | ) |
| = | 8 | x | − | 14 | − | 5 | × | 2 | x | + | 5 | × | 1 |
| = | 8 | x | − | 14 | − | 10 | x | + | 5 |
| = | - | 2 | x | − | 9 |
| - | 2 | x | − | 9 | = | 7 |
| - | 2 | x | = | 7 | + | 9 |
| - | 2 | x | = | 16 |
| - | 16 | = | 2 | x |
| 2 | x | = | - | 16 |
| x | = | - | 16 | ÷ | 2 |
| = | - | 16 | × | 1 2 |
| = | - | 8 | × | 1 |
| x | = | - | 8 |