| ( | 1 | − | 20 100 | ) | x | ÷ | ( | 1 | − | 25 100 | ) | = | 1 5 | x |
| 方程两边同时乘以: | ( | 1 | − | 25 100 | ) |
| ( | 1 | − | 20 100 | ) | x | = | 1 5 | x | ( | 1 | − | 25 100 | ) |
| 1 | x | − | 20 100 | x | = | 1 5 | x | ( | 1 | − | 25 100 | ) |
| 1 | x | − | 20 100 | x | = | 1 5 | x | × | 1 | − | 1 5 | x | × | 25 100 |
| 1 | x | − | 20 100 | x | = | 1 5 | x | − | 1 20 | x |
4 5 | x | = | 3 20 | x |
4 5 | x | − | 3 20 | x | = | 0 |
13 20 | x | = | 0 |
| x | = | 0 | ÷ | 13 20 |
| = | 0 | × | 20 13 |
| x | = | 0 |