( | x | − | 10 | ) | ( | - | 5 | x | + | 150 | ) | = | 0 |
方程左边 = | x | ( | - | 5 | x | + | 150 | ) | − | 10 | ( | - | 5 | x | + | 150 | ) |
= | - | x | × | 5 | x | + | x | × | 150 | − | 10 | ( | - | 5 | x | + | 150 | ) |
= | - | x | × | 5 | x | + | 150 | x | + | 10 | × | 5 | x | − | 10 | × | 150 |
= | - | x | × | 5 | x | + | 150 | x | + | 50 | x | − | 1500 |
= | - | x | × | 5 | x | + | 200 | x | − | 1500 |
- | x | × | 5 | x | + | 200 | x | − | 1500 | = | 0 |