| ( | 2000 | ( | 1 | + | x | ) | − | 1000 | ) | ( | 1 | + | x | ) | − | 1320 | = | 0 |
| 方程左边 = | 2000 | ( | 1 | + | x | ) | ( | 1 | + | x | ) | − | 1000 | ( | 1 | + | x | ) | − | 1320 |
| = | 2000 | × | 1 | ( | 1 | + | x | ) | + | 2000 | x | ( | 1 | + | x | ) | − | 1000 | ( | 1 | + | x | ) | − | 1320 |
| = | 2000 | ( | 1 | + | x | ) | + | 2000 | x | ( | 1 | + | x | ) | − | 1000 | ( | 1 | + | x | ) | − | 1320 |
| = | 2000 | × | 1 | + | 2000 | x | + | 2000 | x | ( | 1 | + | x | ) | − | 1000 | ( | 1 | + | x | ) | − | 1320 |
| = | 2000 | + | 2000 | x | + | 2000 | x | ( | 1 | + | x | ) | − | 1000 | ( | 1 | + | x | ) | − | 1320 |
| = | 680 | + | 2000 | x | + | 2000 | x | ( | 1 | + | x | ) | − | 1000 | ( | 1 | + | x | ) |
| = | 680 | + | 2000 | x | + | 2000 | x | × | 1 | + | 2000 | x | x | − | 1000 | ( | 1 | + | x | ) |
| = | 680 | + | 2000 | x | + | 2000 | x | + | 2000 | x | x | − | 1000 | ( | 1 | + | x | ) |
| = | 680 | + | 4000 | x | + | 2000 | x | x | − | 1000 | ( | 1 | + | x | ) |
| = | 680 | + | 4000 | x | + | 2000 | x | x | − | 1000 | × | 1 | − | 1000 | x |
| = | 680 | + | 4000 | x | + | 2000 | x | x | − | 1000 | − | 1000 | x |
| = | - | 320 | + | 3000 | x | + | 2000 | x | x |
| - | 320 | + | 3000 | x | + | 2000 | x | x | = | 0 |
| x1= | - | 8 5 |
| x2= | 1 10 |