| 15 | = | 100 | ( | X | − | 216 | ) | ÷ | ( | X | × | 160 | ÷ | 100 | ) |
| 方程两边同时乘以: | ( | X | × | 160 | ÷ | 100 | ) |
| 15 | ( | X | × | 160 | ÷ | 100 | ) | = | 100 | ( | X | − | 216 | ) |
| 15 | X | × | 160 | ÷ | 100 | = | 100 | ( | X | − | 216 | ) |
| 15 | X | × | 160 | ÷ | 100 | = | 100 | X | − | 100 | × | 216 |
| 24 | X | = | 100 | X | − | 21600 |
| 24 | X | − | 100 | X | = | - | 21600 |
| - | 76 | X | = | - | 21600 |
| 21600 | = | 76 | X |
| 76 | X | = | 21600 |
| X | = | 21600 | ÷ | 76 |
| = | 21600 | × | 1 76 |
| = | 5400 | × | 1 19 |
| X | = | 5400 19 |
| X | = | 284.210526 |