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