( | - | 12 | x | + | 260 | ) | ( | x | − | 50 | ) | = | 2400 |
方程左边 = | - | 12 | x | ( | x | − | 50 | ) | + | 260 | ( | x | − | 50 | ) |
= | - | 12 | x | x | + | 12 | x | × | 50 | + | 260 | ( | x | − | 50 | ) |
= | - | 12 | x | x | + | 600 | x | + | 260 | ( | x | − | 50 | ) |
= | - | 12 | x | x | + | 600 | x | + | 260 | x | − | 260 | × | 50 |
= | - | 12 | x | x | + | 600 | x | + | 260 | x | − | 13000 |
= | - | 12 | x | x | + | 860 | x | − | 13000 |
- | 12 | x | x | + | 860 | x | − | 13000 | = | 2400 |
x2= | 110 3 |