| 4003 | ( | 5256 | − | x | ) | = | 378 | x |
| 方程左边 = | 4003 | × | 5256 | − | 4003 | x |
| = | 21039768 | − | 4003 | x |
| 21039768 | − | 4003 | x | = | 378 | x |
| - | 4003 | x | − | 378 | x | = | - | 21039768 |
| - | 4381 | x | = | - | 21039768 |
| 21039768 | = | 4381 | x |
| 4381 | x | = | 21039768 |
| x | = | 21039768 | ÷ | 4381 |
| = | 21039768 | × | 1 4381 |
| x | = | 21039768 4381 |
| x | = | 4802.503538 |