| 5 | ( | x | − | 4 | ( | x | − | ( | 57 | ÷ | 10 | ) | ÷ | 6 | ) | ) | = | 4 | x |
| 方程左边 = | 5 | x | − | 5 | × | 4 | ( | x | − | ( | 57 | ÷ | 10 | ) | ÷ | 6 | ) |
| = | 5 | x | − | 20 | ( | x | − | ( | 57 | ÷ | 10 | ) | ÷ | 6 | ) |
| = | 5 | x | − | 20 | x | + | 20 | ( | 57 | ÷ | 10 | ) | ÷ | 6 |
| = | 5 | x | − | 20 | x | + | 10 3 | ( | 57 | ÷ | 10 | ) |
| = | - | 15 | x | + | 10 3 | ( | 57 | ÷ | 10 | ) |
| = | - | 15 | x | + | 10 3 | × | 57 | ÷ | 10 |
| = | - | 15 | x | + | 19 |
| - | 15 | x | + | 19 | = | 4 | x |
| - | 15 | x | − | 4 | x | = | - | 19 |
| - | 19 | x | = | - | 19 |
| 19 | = | 19 | x |
| 19 | x | = | 19 |
| x | = | 19 | ÷ | 19 |
| = | 19 | × | 1 19 |
| = | 1 | × | 1 |
| x | = | 1 |