| ( | x | − | 1 | ) | ( | 2 | − | x | ) | ( | x | − | 5 | ) | = | 0 |
| 方程左边 = | x | ( | 2 | − | x | ) | ( | x | − | 5 | ) | − | 1 | ( | 2 | − | x | ) | ( | x | − | 5 | ) |
| = | x | × | 2 | ( | x | − | 5 | ) | − | x | x | ( | x | − | 5 | ) | − | 1 | ( | 2 | − | x | ) | ( | x | − | 5 | ) |
| = | x | × | 2 | x | − | x | × | 2 | × | 5 | − | x | x | ( | x | − | 5 | ) | − | 1 | ( | 2 | − | x | ) | ( | x | − | 5 | ) |
| = | x | × | 2 | x | − | x | × | 10 | − | x | x | ( | x | − | 5 | ) | − | 1 | ( | 2 | − | x | ) | ( | x | − | 5 | ) |
| = | x | × | 2 | x | − | 10 | x | − | x | x | x | + | x | x | × | 5 | − | 1 |
| = | x | × | 2 | x | − | 10 | x | − | x | x | x | + | x | x | × | 5 | − | 1 |
| = | x | × | 2 | x | − | 10 | x | − | x | x | x | + | x | x | × | 5 | − | 2 |
| = | x | × | 2 | x | − | 10 | x | − | x | x | x | + | x | x | × | 5 | − | 2 |
| = | x | × | 2 | x | − | 10 | x | − | x | x | x | + | x | x | × | 5 | − | 2 |
| = | x | × | 2 | x | − | 12 | x | − | x | x | x | + | x | x | × | 5 | + | 10 |
| = | x | × | 2 | x | − | 12 | x | − | x | x | x | + | x | x | × | 5 | + | 10 |
| = | x | × | 2 | x | − | 12 | x | − | x | x | x | + | x | x | × | 5 | + | 10 |
| = | x | × | 2 | x | − | 17 | x | − | x | x | x | + | x | x | × | 5 | + | 10 |
| x | × | 2 | x | − | 17 | x | − | x | x | x | + | x | x | × | 5 | + | 10 | = | 0 |