| 19 | ÷ | 106 | × | X | = | 21 | ÷ | 100 | × | ( | X | − | 2 | ) |
| 方程左边 = | 19 106 | X |
19 106 | X | = | 21 | ÷ | 100 | × | ( | X | − | 2 | ) |
| 方程右边 = | 21 100 | ( | X | − | 2 | ) |
19 106 | X | = | 21 100 | ( | X | − | 2 | ) |
| 方程右边 = | 21 100 | X | − | 21 100 | × | 2 |
| = | 21 100 | X | − | 21 50 |
19 106 | X | = | 21 100 | X | − | 21 50 |
19 106 | X | − | 21 100 | X | = | - | 21 50 |
| - | 163 5300 | X | = | - | 21 50 |
21 50 | = | 163 5300 | X |
163 5300 | X | = | 21 50 |
| X | = | 21 50 | ÷ | 163 5300 |
| = | 21 50 | × | 5300 163 |
| = | 21 | × | 106 163 |
| X | = | 2226 163 |
| X | = | 13.656442 |