| 500 | + | ( | ( | x | − | 500 | ) | × | 10 100 | ) | = | x |
| 方程左边 = | 500 | + | ( | x | − | 500 | ) | × | 10 100 |
| = | 500 | + | x | × | 10 100 | − | 500 | × | 10 100 |
| = | 500 | + | x | × | 10 100 | − | 50 |
| = | 450 | + | 10 100 | x |
| 450 | + | 10 100 | x | = | x |
10 100 | x | − | x | = | - | 450 |
| - | 9 10 | x | = | - | 450 |
| 450 | = | 9 10 | x |
9 10 | x | = | 450 |
| x | = | 450 | ÷ | 9 10 |
| = | 450 | × | 10 9 |
| = | 50 | × | 10 |
| x | = | 500 |