( | 7 | x | + | 6 | ) | ( | 10 | − | 5 | x | ) | = | 0 |
方程左边 = | 7 | x | ( | 10 | − | 5 | x | ) | + | 6 | ( | 10 | − | 5 | x | ) |
= | 7 | x | × | 10 | − | 7 | x | × | 5 | x | + | 6 | ( | 10 | − | 5 | x | ) |
= | 70 | x | − | 35 | x | x | + | 6 | ( | 10 | − | 5 | x | ) |
= | 70 | x | − | 35 | x | x | + | 6 | × | 10 | − | 6 | × | 5 | x |
= | 70 | x | − | 35 | x | x | + | 60 | − | 30 | x |
= | 40 | x | − | 35 | x | x | + | 60 |
40 | x | − | 35 | x | x | + | 60 | = | 0 |
x1= | - | 6 7 |
x2=2 |