- | 4 | ( | x | + | 1 | ) | ( | x | − | 2 | ) | = | 1 |
方程左边 = | - | 4 | x | ( | x | − | 2 | ) | − | 4 | × | 1 | ( | x | − | 2 | ) |
= | - | 4 | x | ( | x | − | 2 | ) | − | 4 | ( | x | − | 2 | ) |
= | - | 4 | x | x | + | 4 | x | × | 2 | − | 4 | ( | x | − | 2 | ) |
= | - | 4 | x | x | + | 8 | x | − | 4 | ( | x | − | 2 | ) |
= | - | 4 | x | x | + | 8 | x | − | 4 | x | + | 4 | × | 2 |
= | - | 4 | x | x | + | 8 | x | − | 4 | x | + | 8 |
= | - | 4 | x | x | + | 4 | x | + | 8 |
- | 4 | x | x | + | 4 | x | + | 8 | = | 1 |