| 1 | + | 2 | ( | x | + | 3 | ) | = | 4 | + | 4 | ( | x | − | 6 | ) | − | 7 |
| 方程左边 = | 1 | + | 2 | x | + | 2 | × | 3 |
| = | 1 | + | 2 | x | + | 6 |
| = | 7 | + | 2 | x |
| 7 | + | 2 | x | = | 4 | + | 4 | ( | x | − | 6 | ) | − | 7 |
| 方程右边 = | - | 3 | + | 4 | ( | x | − | 6 | ) |
| 7 | + | 2 | x | = | - | 3 | + | 4 | ( | x | − | 6 | ) |
| 方程右边 = | - | 3 | + | 4 | x | − | 4 | × | 6 |
| = | - | 3 | + | 4 | x | − | 24 |
| = | - | 27 | + | 4 | x |
| 7 | + | 2 | x | = | - | 27 | + | 4 | x |
| 2 | x | − | 4 | x | = | - | 27 | − | 7 |
| - | 2 | x | = | - | 27 | − | 7 |
| - | 2 | x | = | - | 34 |
| 34 | = | 2 | x |
| 2 | x | = | 34 |
| x | = | 34 | ÷ | 2 |
| = | 34 | × | 1 2 |
| = | 17 | × | 1 |
| x | = | 17 |