| ( | 1 5 | − | x | ) | ÷ | ( | 7 25 | − | x | ) | × | 7 25 | ÷ | 1 5 | = | 4 5 |
| 方程两边同时乘以: | ( | 7 25 | − | x | ) |
| ( | 1 5 | − | x | ) | × | 7 25 | ÷ | 1 5 | = | 4 5 | ( | 7 25 | − | x | ) |
1 5 | × | 7 25 | ÷ | 1 5 | − | x | × | 7 25 | ÷ | 1 5 | = | 4 5 | ( | 7 25 | − | x | ) |
1 5 | × | 7 25 | ÷ | 1 5 | − | x | × | 7 25 | ÷ | 1 5 | = | 4 5 | × | 7 25 | − | 4 5 | x |
7 25 | − | x | × | 7 5 | = | 28 125 | − | 4 5 | x |
| - | 7 5 | x | + | 4 5 | x | = | 28 125 | − | 7 25 |
| - | 3 5 | x | = | 28 125 | − | 7 25 |
| - | 3 5 | x | = | - | 7 125 |
7 125 | = | 3 5 | x |
3 5 | x | = | 7 125 |
| x | = | 7 125 | ÷ | 3 5 |
| = | 7 125 | × | 5 3 |
| = | 7 25 | × | 1 3 |
| x | = | 7 75 |
| x | = | 0.093333 |