| 11000 | − | P | = | ( | 15000 | − | P | ) | × | 3571 10000 | ÷ | 21 20 |
| 方程右边 = | ( | 15000 | − | P | ) | × | 3571 10500 |
| 11000 | − | P | = | ( | 15000 | − | P | ) | × | 3571 10500 |
| 方程右边 = | 15000 | × | 3571 10500 | − | P | × | 3571 10500 |
| = | 35710 7 | − | P | × | 3571 10500 |
| 11000 | − | P | = | 35710 7 | − | 3571 10500 | P |
| - | P | + | 3571 10500 | P | = | 35710 7 | − | 11000 |
| - | 6929 10500 | P | = | 35710 7 | − | 11000 |
| - | 6929 10500 | P | = | - | 41290 7 |
41290 7 | = | 6929 10500 | P |
6929 10500 | P | = | 41290 7 |
| P | = | 41290 7 | ÷ | 6929 10500 |
| = | 41290 7 | × | 10500 6929 |
| = | 41290 | × | 1500 6929 |
| P | = | 61935000 6929 |
| P | = | 8938.519267 |