| ( | 1 50 | − | x | ) | ( | 1 25 | − | x | ) | = | 9 50000000000 |
| 方程左边 = | 1 50 | ( | 1 25 | − | x | ) | − | x | ( | 1 25 | − | x | ) |
| = | 1 50 | × | 1 25 | − | 1 50 | x | − | x | ( | 1 25 | − | x | ) |
| = | 1 1250 | − | 1 50 | x | − | x | ( | 1 25 | − | x | ) |
| = | 1 1250 | − | 1 50 | x | − | x | × | 1 25 | + | x | x |
| = | 1 1250 | − | 3 50 | x | + | x | x |
1 1250 | − | 3 50 | x | + | x | x | = | 9 50000000000 |