| 4000 | × | 80 100 | ( | 1 | + | X | ) | × | 93 100 | − | 4000 | × | 20 100 | = | 4000 |
| 方程左边 = | 2976 | ( | 1 | + | X | ) | − | 800 |
| 2976 | ( | 1 | + | X | ) | − | 800 | = | 4000 |
| 方程左边 = | 2976 | × | 1 | + | 2976 | X | − | 800 |
| = | 2976 | + | 2976 | X | − | 800 |
| = | 2176 | + | 2976 | X |
| 2176 | + | 2976 | X | = | 4000 |
| 2976 | X | = | 4000 | − | 2176 |
| 2976 | X | = | 1824 |
| X | = | 1824 | ÷ | 2976 |
| = | 1824 | × | 1 2976 |
| = | 19 | × | 1 31 |
| X | = | 19 31 |
| X | = | 0.612903 |