| ( | 3 | ÷ | 5 | ) | ( | 20 | ÷ | 6 | ) | − | ( | 3 | ÷ | 5 | ) | x | = | 20 | − | x |
| 方程左边 = | 3 | ÷ | 5 | × | ( | 20 | ÷ | 6 | ) | − | ( | 3 | ÷ | 5 | ) | x |
| = | 3 5 | ( | 20 | ÷ | 6 | ) | − | ( | 3 | ÷ | 5 | ) | x |
| = | 3 5 | × | 20 | ÷ | 6 | − | ( | 3 | ÷ | 5 | ) | x |
| = | 2 | − | ( | 3 | ÷ | 5 | ) | x |
| = | 2 | − | 3 | ÷ | 5 | × | x |
| = | 2 | − | 3 5 | x |
| 2 | − | 3 5 | x | = | 20 | − | x |
| - | 3 5 | x | + | x | = | 20 | − | 2 |
| - | - | 2 5 | x | = | 20 | − | 2 |
| - | - | 2 5 | x | = | 18 |
| - | 18 | = | - | 2 5 | x |
| - | 2 5 | x | = | - | 18 |
| x | = | 18 | ÷ | 2 5 |
| = | 18 | × | 5 2 |
| = | 9 | × | 5 |
| x | = | 45 |