| 1000 | = | x | ÷ | ( | 1 | − | 50 100 | ) | ÷ | 30 100 |
| 方程两边同时乘以: | ( | 1 | − | 50 100 | ) |
| 1000 | ( | 1 | − | 50 100 | ) | = | x | ÷ | 30 100 |
| 1000 | × | 1 | − | 1000 | × | 50 100 | = | x | ÷ | 30 100 |
| 1000 | − | 500 | = | x | × | 100 30 |
| 500 | = | 100 30 | x |
| - | 100 30 | x | = | - | 500 |
| 500 | = | 100 30 | x |
100 30 | x | = | 500 |
| x | = | 500 | ÷ | 100 30 |
| = | 500 | × | 30 100 |
| = | 5 | × | 30 |
| x | = | 150 |