| ( | x | − | 558802 | ) | ÷ | 21 20 | × | 1 20 | = | x | − | 1359597 |
| 方程左边 = | ( | x | − | 558802 | ) | × | 1 21 |
| ( | x | − | 558802 | ) | × | 1 21 | = | x | − | 1359597 |
| 方程左边 = | x | × | 1 21 | − | 558802 | × | 1 21 |
| = | x | × | 1 21 | − | 558802 21 |
1 21 | x | − | 558802 21 | = | x | − | 1359597 |
1 21 | x | − | x | = | - | 1359597 | + | 558802 21 |
| - | 20 21 | x | = | - | 1359597 | + | 558802 21 |
| - | 20 21 | x | = | - | 27992735 21 |
27992735 21 | = | 20 21 | x |
20 21 | x | = | 27992735 21 |
| x | = | 27992735 21 | ÷ | 20 21 |
| = | 27992735 21 | × | 21 20 |
| = | 5598547 | × | 1 4 |
| x | = | 5598547 4 |
| x | = | 1399636.75 |