| ( | 17000 | − | X | ) | ÷ | 5000 | = | ( | 19500 | − | X | ) | ÷ | 6000 |
| 方程左边 = | 17000 | × | 1 5000 | − | X | × | 1 5000 |
| = | 17 5 | − | X | × | 1 5000 |
17 5 | − | 1 5000 | X | = | ( | 19500 | − | X | ) | ÷ | 6000 |
| 方程右边 = | 19500 | × | 1 6000 | − | X | × | 1 6000 |
| = | 13 4 | − | X | × | 1 6000 |
17 5 | − | 1 5000 | X | = | 13 4 | − | 1 6000 | X |
| - | 1 5000 | X | + | 1 6000 | X | = | 13 4 | − | 17 5 |
| - | 1 30000 | X | = | 13 4 | − | 17 5 |
| - | 1 30000 | X | = | - | 3 20 |
3 20 | = | 1 30000 | X |
1 30000 | X | = | 3 20 |
| X | = | 3 20 | ÷ | 1 30000 |
| = | 3 20 | × | 30000 |
| = | 3 | × | 1500 |
| X | = | 4500 |