| X | − | ( | 19600 | + | X | − | 25000 | ) | × | 3 100 | = | 8400 |
| 方程左边 = | X | − | 19600 | × | 3 100 | − | X | × | 3 100 | + | 25000 | × | 3 100 |
| = | X | − | 588 | − | X | × | 3 100 | + | 750 |
| = | 97 100 | X | + | 162 |
97 100 | X | + | 162 | = | 8400 |
97 100 | X | = | 8400 | − | 162 |
97 100 | X | = | 8238 |
| X | = | 8238 | ÷ | 97 100 |
| = | 8238 | × | 100 97 |
| X | = | 823800 97 |
| X | = | 8492.783505 |