| 10000 | X | × | 1 4 | = | 10000 | X | − | 10000 | X | × | 1 20 | − | 2850000 |
| 方程左边 = | 2500 | X |
| 2500 | X | = | 10000 | X | − | 10000 | X | × | 1 20 | − | 2850000 |
| 方程右边 = | 10000 | X | − | 500 | X | − | 2850000 |
| = | 9500 | X | − | 2850000 |
| 2500 | X | = | 9500 | X | − | 2850000 |
| 2500 | X | − | 9500 | X | = | - | 2850000 |
| - | 7000 | X | = | - | 2850000 |
| 2850000 | = | 7000 | X |
| 7000 | X | = | 2850000 |
| X | = | 2850000 | ÷ | 7000 |
| = | 2850000 | × | 1 7000 |
| = | 2850 | × | 1 7 |
| X | = | 2850 7 |
| X | = | 407.142857 |