| ( | 9100 | − | X | ) | ÷ | 70000 | = | 0 |
| 方程左边 = | 9100 | × | 1 70000 | − | X | × | 1 70000 |
| = | 13 100 | − | X | × | 1 70000 |
13 100 | − | 1 70000 | X | = | 0 |
| - | 1 70000 | X | = | 0 | − | 13 100 |
| - | 1 70000 | X | = | - | 13 100 |
13 100 | = | 1 70000 | X |
1 70000 | X | = | 13 100 |
| X | = | 13 100 | ÷ | 1 70000 |
| = | 13 100 | × | 70000 |
| = | 13 | × | 700 |
| X | = | 9100 |