| ( | 8417 10 | + | X | ) | × | 7 20 | = | X |
| 方程左边 = | 8417 10 | × | 7 20 | + | X | × | 7 20 |
| = | 58919 200 | + | X | × | 7 20 |
58919 200 | + | 7 20 | X | = | X |
7 20 | X | − | X | = | - | 58919 200 |
| - | 13 20 | X | = | - | 58919 200 |
58919 200 | = | 13 20 | X |
13 20 | X | = | 58919 200 |
| X | = | 58919 200 | ÷ | 13 20 |
| = | 58919 200 | × | 20 13 |
| = | 58919 10 | × | 1 13 |
| X | = | 58919 130 |
| X | = | 453.223077 |