| 800 | ÷ | x | = | ( | 500 | ÷ | x | + | 5 | ) | × | 2 |
| 方程两边同时乘以: | x |
| 800 | = | ( | 500 | ÷ | x | + | 5 | ) | × | 2 | x |
| 800 | = | 500 | ÷ | x | × | 2 | x | + | 5 | × | 2 | x |
| 800 | = | 1000 | ÷ | x | × | x | + | 10 | x |
| - | 10 | x | = | 1000 | ÷ | 1 | × | 1 | − | 800 |
| - | 10 | x | = | 1000 | − | 800 |
| - | 10 | x | = | 200 |
| - | 200 | = | 10 | x |
| 10 | x | = | - | 200 |
| x | = | - | 200 | ÷ | 10 |
| = | - | 200 | × | 1 10 |
| = | - | 20 | × | 1 |
| x | = | - | 20 |