| 5 | + | 3 | ( | 2 | + | 7 | ( | 7 | + | x | ) | ) | = | 11 | ( | x | − | 2 | ) |
| 方程左边 = | 5 | + | 3 | × | 2 | + | 3 | × | 7 | ( | 7 | + | x | ) |
| = | 5 | + | 6 | + | 21 | ( | 7 | + | x | ) |
| = | 11 | + | 21 | ( | 7 | + | x | ) |
| = | 11 | + | 21 | × | 7 | + | 21 | x |
| = | 11 | + | 147 | + | 21 | x |
| = | 158 | + | 21 | x |
| 158 | + | 21 | x | = | 11 | ( | x | − | 2 | ) |
| 方程右边 = | 11 | x | − | 11 | × | 2 |
| = | 11 | x | − | 22 |
| 158 | + | 21 | x | = | 11 | x | − | 22 |
| 21 | x | − | 11 | x | = | - | 22 | − | 158 |
| 10 | x | = | - | 22 | − | 158 |
| 10 | x | = | - | 180 |
| x | = | - | 180 | ÷ | 10 |
| = | - | 180 | × | 1 10 |
| = | - | 18 | × | 1 |
| x | = | - | 18 |