| ( | 11 | − | 1 50 | x | ) | ( | 11 | − | 1 50 | x | ) | = | 1 25 | ( | 999 | − | 11 | x | ) |
| 方程左边 = | 11 | ( | 11 | − | 1 50 | x | ) | − | 1 50 | x | ( | 11 | − | 1 50 | x | ) |
| = | 11 | × | 11 | − | 11 | × | 1 50 | x | − | 1 50 | x | ( | 11 | − | 1 50 | x | ) |
| = | 121 | − | 11 50 | x | − | 1 50 | x | ( | 11 | − | 1 50 | x | ) |
| = | 121 | − | 11 50 | x | − | 1 50 | x | × | 11 | + | 1 50 | x | × | 1 50 | x |
| = | 121 | − | 11 50 | x | − | 11 50 | x | + | 1 2500 | x | x |
| = | 121 | − | 11 25 | x | + | 1 2500 | x | x |
| 121 | − | 11 25 | x | + | 1 2500 | x | x | = | 1 25 | ( | 999 | − | 11 | x | ) |
| 方程右边 = | 1 25 | × | 999 | − | 1 25 | × | 11 | x |
| = | 999 25 | − | 11 25 | x |
| 121 | − | 11 25 | x | + | 1 2500 | x | x | = | 999 25 | − | 11 25 | x |