| ( | 6813 | − | x | ) | ÷ | ( | 21212 | − | x | ) | = | 7 25 |
| 方程两边同时乘以: | ( | 21212 | − | x | ) |
| ( | 6813 | − | x | ) | = | 7 25 | ( | 21212 | − | x | ) |
| 6813 | − | x | = | 7 25 | ( | 21212 | − | x | ) |
| 6813 | − | x | = | 7 25 | × | 21212 | − | 7 25 | x |
| 6813 | − | x | = | 148484 25 | − | 7 25 | x |
| - | x | + | 7 25 | x | = | 148484 25 | − | 6813 |
| - | 18 25 | x | = | 148484 25 | − | 6813 |
| - | 18 25 | x | = | - | 21841 25 |
21841 25 | = | 18 25 | x |
18 25 | x | = | 21841 25 |
| x | = | 21841 25 | ÷ | 18 25 |
| = | 21841 25 | × | 25 18 |
| = | 21841 | × | 1 18 |
| x | = | 21841 18 |
| x | = | 1213.388889 |