| 11200000 | = | 10000 | ( | 18000 | − | x | ) | − | 50000000 |
| 方程右边 = | 10000 | × | 18000 | − | 10000 | x | − | 50000000 |
| = | 180000000 | − | 10000 | x | − | 50000000 |
| = | 130000000 | − | 10000 | x |
| 11200000 | = | 130000000 | − | 10000 | x |
| 10000 | x | = | 130000000 | − | 11200000 |
| 10000 | x | = | 118800000 |
| x | = | 118800000 | ÷ | 10000 |
| = | 118800000 | × | 1 10000 |
| = | 11880 | × | 1 |
| x | = | 11880 |