| 4 | ( | 2 | x | − | 7 | ) | − | 2 | ( | x | − | 1 | ) | = | 3 | x | − | 5 |
| 方程左边 = | 4 | × | 2 | x | − | 4 | × | 7 | − | 2 | ( | x | − | 1 | ) |
| = | 8 | x | − | 28 | − | 2 | ( | x | − | 1 | ) |
| = | 8 | x | − | 28 | − | 2 | x | + | 2 | × | 1 |
| = | 8 | x | − | 28 | − | 2 | x | + | 2 |
| = | 6 | x | − | 26 |
| 6 | x | − | 26 | = | 3 | x | − | 5 |
| 6 | x | − | 3 | x | = | - | 5 | + | 26 |
| 3 | x | = | - | 5 | + | 26 |
| 3 | x | = | 21 |
| x | = | 21 | ÷ | 3 |
| = | 21 | × | 1 3 |
| = | 7 | × | 1 |
| x | = | 7 |