| 500 | × | 500 | + | ( | 10000 | − | x | ) | ( | 10000 | − | x | ) | = | 10000 | × | 10000 |
| 方程左边 = | 250000 | + | ( | 10000 | − | x | ) | ( | 10000 | − | x | ) |
| 250000 | + | ( | 10000 | − | x | ) | ( | 10000 | − | x | ) | = | 10000 | × | 10000 |
| 方程左边 = | 250000 | + | 10000 | ( | 10000 | − | x | ) | − | x | ( | 10000 | − | x | ) |
| = | 250000 | + | 10000 | × | 10000 | − | 10000 | x | − | x | ( | 10000 | − | x | ) |
| = | 250000 | + | 100000000 | − | 10000 | x | − | x | ( | 10000 | − | x | ) |
| = | 100250000 | − | 10000 | x | − | x | ( | 10000 | − | x | ) |
| = | 100250000 | − | 10000 | x | − | x | × | 10000 | + | x | x |
| = | 100250000 | − | 20000 | x | + | x | x |
| 100250000 | − | 20000 | x | + | x | x | = | 10000 | × | 10000 |
| 方程右边 = | 100000000 |
| 100250000 | − | 20000 | x | + | x | x | = | 100000000 |