| 4 | ( | 2 | × | 3 | − | 5 | x | ) | − | 3 | = | - | ( | 3 | − | 7 | x | ) |
| 方程左边 = | 4 | × | 2 | × | 3 | − | 4 | × | 5 | x | − | 3 |
| = | 24 | − | 20 | x | − | 3 |
| = | 21 | − | 20 | x |
| 21 | − | 20 | x | = | - | ( | 3 | − | 7 | x | ) |
| 方程右边 = | - | 3 | + | 7 | x |
| 21 | − | 20 | x | = | - | 3 | + | 7 | x |
| - | 20 | x | − | 7 | x | = | - | 3 | − | 21 |
| - | 27 | x | = | - | 3 | − | 21 |
| - | 27 | x | = | - | 24 |
| 24 | = | 27 | x |
| 27 | x | = | 24 |
| x | = | 24 | ÷ | 27 |
| = | 24 | × | 1 27 |
| = | 8 | × | 1 9 |
| x | = | 8 9 |
| x | = | 0.888889 |