| ( | x | − | 1 | ) | ( | x | − | 4 | ) | − | 2 | ( | x | − | 3 | ) | = | 0 |
| 方程左边 = | x | ( | x | − | 4 | ) | − | 1 | ( | x | − | 4 | ) | − | 2 | ( | x | − | 3 | ) |
| = | x | x | − | x | × | 4 | − | 1 | ( | x | − | 4 | ) | − | 2 | ( | x | − | 3 | ) |
| = | x | x | − | 4 | x | − | 1 | x | + | 1 | × | 4 | − | 2 | ( | x | − | 3 | ) |
| = | x | x | − | 4 | x | − | 1 | x | + | 4 | − | 2 | ( | x | − | 3 | ) |
| = | x | x | − | 5 | x | + | 4 | − | 2 | ( | x | − | 3 | ) |
| = | x | x | − | 5 | x | + | 4 | − | 2 | x | + | 2 | × | 3 |
| = | x | x | − | 5 | x | + | 4 | − | 2 | x | + | 6 |
| = | x | x | − | 7 | x | + | 10 |
| x | x | − | 7 | x | + | 10 | = | 0 |