| X | − | ( | ( | X | − | 5000 | ) | × | 1 5 | − | 169201 | ) | = | 25000 |
| 方程左边 = | X | − | ( | X | − | 5000 | ) | × | 1 5 | + | 169201 |
| = | X | − | X | × | 1 5 | + | 5000 | × | 1 5 | + | 169201 |
| = | X | − | X | × | 1 5 | + | 1000 | + | 169201 |
| = | 4 5 | X | + | 170201 |
4 5 | X | + | 170201 | = | 25000 |
4 5 | X | = | 25000 | − | 170201 |
4 5 | X | = | - | 145201 |
| X | = | - | 145201 | ÷ | 4 5 |
| = | - | 145201 | × | 5 4 |
| X | = | - | 726005 4 |
| X | = | - 181501.25 |