| ( | 1 | − | 2 | x | ) | ( | x | − | 1 | ) | ( | x | − | 2 | ) | = | 0 |
| 方程左边 = | 1 | ( | x | − | 1 | ) | ( | x | − | 2 | ) | − | 2 | x | ( | x | − | 1 | ) | ( | x | − | 2 | ) |
| = | 1 | x | ( | x | − | 2 | ) | − | 1 | × | 1 | ( | x | − | 2 | ) | − | 2 | x | ( | x | − | 1 | ) | ( | x | − | 2 | ) |
| = | 1 | x | ( | x | − | 2 | ) | − | 1 | ( | x | − | 2 | ) | − | 2 | x | ( | x | − | 1 | ) | ( | x | − | 2 | ) |
| = | 1 | x | x | − | 1 | x | × | 2 | − | 1 | ( | x | − | 2 | ) | − | 2 | x | ( | x | − | 1 | ) | ( | x | − | 2 | ) |
| = | 1 | x | x | − | 2 | x | − | 1 | ( | x | − | 2 | ) | − | 2 | x | ( | x | − | 1 | ) | ( | x | − | 2 | ) |
| = | 1 | x | x | − | 2 | x | − | 1 | x | + | 1 | × | 2 | − | 2 | x | ( | x | − | 1 | ) |
| = | 1 | x | x | − | 2 | x | − | 1 | x | + | 2 | − | 2 | x | ( | x | − | 1 | ) | ( | x | − | 2 | ) |
| = | 1 | x | x | − | 3 | x | + | 2 | − | 2 | x | ( | x | − | 1 | ) | ( | x | − | 2 | ) |
| = | 1 | x | x | − | 3 | x | + | 2 | − | 2 | x | x | ( | x | − | 2 | ) | + | 2 | x |
| = | 1 | x | x | − | 3 | x | + | 2 | − | 2 | x | x | ( | x | − | 2 | ) | + | 2 | x |
| = | 1 | x | x | − | 3 | x | + | 2 | − | 2 | x | x | x | + | 2 | x |
| = | 1 | x | x | − | 3 | x | + | 2 | − | 2 | x | x | x | + | 4 | x |
| = | 1 | x | x | − | 3 | x | + | 2 | − | 2 | x | x | x | + | 4 | x |
| = | 1 | x | x | − | 3 | x | + | 2 | − | 2 | x | x | x | + | 4 | x |
| = | 1 | x | x | − | 7 | x | + | 2 | − | 2 | x | x | x | + | 4 | x |
| 1 | x | x | − | 7 | x | + | 2 | − | 2 | x | x | x | + | 4 | x | = | 0 |
| x1= | 1 2 |
| x2=1 |
| x3=2 |