| ( | 440 | × | 63 | − | x | ) | × | 17 20 | = | 423509 20 |
| 方程左边 = | 440 | × | 63 | × | 17 20 | − | x | × | 17 20 |
| = | 23562 | − | x | × | 17 20 |
| 23562 | − | 17 20 | x | = | 423509 20 |
| - | 17 20 | x | = | 423509 20 | − | 23562 |
| - | 17 20 | x | = | - | 47731 20 |
47731 20 | = | 17 20 | x |
17 20 | x | = | 47731 20 |
| x | = | 47731 20 | ÷ | 17 20 |
| = | 47731 20 | × | 20 17 |
| = | 47731 | × | 1 17 |
| x | = | 47731 17 |
| x | = | 2807.705882 |