| ( | 95 | − | X | ) | ÷ | ( | 100 | − | X | ) | = | 1012 5 | ÷ | 220 |
| 方程两边同时乘以: | ( | 100 | − | X | ) |
| ( | 95 | − | X | ) | = | 1012 5 | ÷ | 220 | × | ( | 100 | − | X | ) |
| 95 | − | X | = | 1012 5 | ÷ | 220 | × | ( | 100 | − | X | ) |
| 95 | − | X | = | 1012 5 | ÷ | 220 | × | 100 | − | 1012 5 | ÷ | 220 | × | X |
| 95 | − | X | = | 92 | − | 23 25 | X |
| - | X | + | 23 25 | X | = | 92 | − | 95 |
| - | 2 25 | X | = | 92 | − | 95 |
| - | 2 25 | X | = | - | 3 |
| 3 | = | 2 25 | X |
2 25 | X | = | 3 |
| X | = | 3 | ÷ | 2 25 |
| = | 3 | × | 25 2 |
| X | = | 75 2 |
| X | = | 37.5 |