| X | ÷ | ( | X | − | 1182 125 | ) | = | 21 5 |
| 方程两边同时乘以: | ( | X | − | 1182 125 | ) |
| X | = | 21 5 | ( | X | − | 1182 125 | ) |
| X | = | 21 5 | X | − | 21 5 | × | 1182 125 |
| X | = | 21 5 | X | − | 24822 625 |
| X | − | 21 5 | X | = | - | 24822 625 |
| - | 16 5 | X | = | - | 24822 625 |
24822 625 | = | 16 5 | X |
16 5 | X | = | 24822 625 |
| X | = | 24822 625 | ÷ | 16 5 |
| = | 24822 625 | × | 5 16 |
| = | 12411 125 | × | 1 8 |
| X | = | 12411 1000 |
| X | = | 12.411 |