| ( | 40000 | ( | 1 | + | x | ) | − | 20000 | ) | ( | 1 | + | x | ) | = | 579101 25 |
| 方程左边 = | 40000 | ( | 1 | + | x | ) | ( | 1 | + | x | ) | − | 20000 | ( | 1 | + | x | ) |
| = | 40000 | × | 1 | ( | 1 | + | x | ) | + | 40000 | x | ( | 1 | + | x | ) | − | 20000 | ( | 1 | + | x | ) |
| = | 40000 | ( | 1 | + | x | ) | + | 40000 | x | ( | 1 | + | x | ) | − | 20000 | ( | 1 | + | x | ) |
| = | 40000 | × | 1 | + | 40000 | x | + | 40000 | x | ( | 1 | + | x | ) | − | 20000 | ( | 1 | + | x | ) |
| = | 40000 | + | 40000 | x | + | 40000 | x | ( | 1 | + | x | ) | − | 20000 | ( | 1 | + | x | ) |
| = | 40000 | + | 40000 | x | + | 40000 | x | × | 1 | + | 40000 | x | x | − | 20000 | ( | 1 | + | x | ) |
| = | 40000 | + | 40000 | x | + | 40000 | x | + | 40000 | x | x | − | 20000 | ( | 1 | + | x | ) |
| = | 40000 | + | 80000 | x | + | 40000 | x | x | − | 20000 | ( | 1 | + | x | ) |
| = | 40000 | + | 80000 | x | + | 40000 | x | x | − | 20000 | × | 1 | − | 20000 | x |
| = | 40000 | + | 80000 | x | + | 40000 | x | x | − | 20000 | − | 20000 | x |
| = | 20000 | + | 60000 | x | + | 40000 | x | x |
| 20000 | + | 60000 | x | + | 40000 | x | x | = | 579101 25 |
| x1= | - | 1551 1000 |
| x2= | 51 1000 |