| ( | x | − | 33 1000 | ) | ( | x | − | 20 100 | ) | = | ( | x | − | 7 100 | ) | ( | x | − | 33 100 | ) |
| 方程左边 = | x | ( | x | − | 20 100 | ) | − | 33 1000 | ( | x | − | 20 100 | ) |
| = | x | x | − | x | × | 20 100 | − | 33 1000 | ( | x | − | 20 100 | ) |
| = | x | x | − | 20 100 | x | − | 33 1000 | x | + | 33 1000 | × | 20 100 |
| = | x | x | − | 20 100 | x | − | 33 1000 | x | + | 33 5000 |
| = | x | x | − | 233 1000 | x | + | 33 5000 |
| x | x | − | 233 1000 | x | + | 33 5000 | = | ( | x | − | 7 100 | ) | ( | x | − | 33 100 | ) |
| 方程右边 = | x | ( | x | − | 33 100 | ) | − | 7 100 | ( | x | − | 33 100 | ) |
| = | x | x | − | x | × | 33 100 | − | 7 100 | ( | x | − | 33 100 | ) |
| = | x | x | − | 33 100 | x | − | 7 100 | x | + | 7 100 | × | 33 100 |
| = | x | x | − | 33 100 | x | − | 7 100 | x | + | 231 10000 |
| = | x | x | − | 2 5 | x | + | 231 10000 |
| x | x | − | 233 1000 | x | + | 33 5000 | = | x | x | − | 2 5 | x | + | 231 10000 |