| 1500 | × | 1500 | = | 250 | ( | 2 | R | − | 250 | ) |
| 方程左边 = | 2250000 |
| 2250000 | = | 250 | ( | 2 | R | − | 250 | ) |
| 方程右边 = | 250 | × | 2 | R | − | 250 | × | 250 |
| = | 500 | R | − | 62500 |
| 2250000 | = | 500 | R | − | 62500 |
| - | 500 | R | = | - | 62500 | − | 2250000 |
| - | 500 | R | = | - | 2312500 |
| 2312500 | = | 500 | R |
| 500 | R | = | 2312500 |
| R | = | 2312500 | ÷ | 500 |
| = | 2312500 | × | 1 500 |
| = | 4625 | × | 1 |
| R | = | 4625 |