| 320000 | = | ( | 1100000 | − | ( | 100000 | + | X | ) | ) | × | 3 10 | + | X |
| 方程右边 = | 1100000 | × | 3 10 | − | ( | 100000 | + | X | ) | × | 3 10 | + | X |
| = | 330000 | − | ( | 100000 | + | X | ) | × | 3 10 | + | X |
| = | 330000 | − | 100000 | × | 3 10 | − | X | × | 3 10 | + | X |
| = | 330000 | − | 30000 | − | X | × | 3 10 | + | X |
| = | 300000 | + | 7 10 | X |
| 320000 | = | 300000 | + | 7 10 | X |
| - | 7 10 | X | = | 300000 | − | 320000 |
| - | 7 10 | X | = | - | 20000 |
| 20000 | = | 7 10 | X |
7 10 | X | = | 20000 |
| X | = | 20000 | ÷ | 7 10 |
| = | 20000 | × | 10 7 |
| X | = | 200000 7 |
| X | = | 28571.428571 |