| 50000 | = | ( | X | − | 50 | ) | × | 1800 | − | 50000 |
| 方程右边 = | X | × | 1800 | − | 50 | × | 1800 | − | 50000 |
| = | X | × | 1800 | − | 90000 | − | 50000 |
| = | 1800 | X | − | 140000 |
| 50000 | = | 1800 | X | − | 140000 |
| - | 1800 | X | = | - | 140000 | − | 50000 |
| - | 1800 | X | = | - | 190000 |
| 190000 | = | 1800 | X |
| 1800 | X | = | 190000 |
| X | = | 190000 | ÷ | 1800 |
| = | 190000 | × | 1 1800 |
| = | 950 | × | 1 9 |
| X | = | 950 9 |
| X | = | 105.555556 |