| ( | 500 | − | x | ) | × | 4 | ÷ | 60 | = | ( | 400 | − | x | ) | × | 6 | ÷ | 60 |
| 方程左边 = | ( | 500 | − | x | ) | × | 1 15 |
| ( | 500 | − | x | ) | × | 1 15 | = | ( | 400 | − | x | ) | × | 6 | ÷ | 60 |
| 方程左边 = | 500 | × | 1 15 | − | x | × | 1 15 |
| = | 100 3 | − | x | × | 1 15 |
100 3 | − | 1 15 | x | = | ( | 400 | − | x | ) | × | 6 | ÷ | 60 |
| 方程右边 = | ( | 400 | − | x | ) | × | 1 10 |
100 3 | − | 1 15 | x | = | ( | 400 | − | x | ) | × | 1 10 |
| 方程右边 = | 400 | × | 1 10 | − | x | × | 1 10 |
| = | 40 | − | x | × | 1 10 |
100 3 | − | 1 15 | x | = | 40 | − | 1 10 | x |
| - | 1 15 | x | + | 1 10 | x | = | 40 | − | 100 3 |
1 30 | x | = | 40 | − | 100 3 |
1 30 | x | = | 20 3 |
| x | = | 20 3 | ÷ | 1 30 |
| = | 20 3 | × | 30 |
| = | 20 | × | 10 |
| x | = | 200 |