300 | ( | 1 | − | x | ) | ( | 1 | − | 2 | x | ) | = | 144 |
方程左边 = | 300 | × | 1 | ( | 1 | − | 2 | x | ) | − | 300 | x | ( | 1 | − | 2 | x | ) |
= | 300 | ( | 1 | − | 2 | x | ) | − | 300 | x | ( | 1 | − | 2 | x | ) |
= | 300 | × | 1 | − | 300 | × | 2 | x | − | 300 | x | ( | 1 | − | 2 | x | ) |
= | 300 | − | 600 | x | − | 300 | x | ( | 1 | − | 2 | x | ) |
= | 300 | − | 600 | x | − | 300 | x | × | 1 | + | 300 | x | × | 2 | x |
= | 300 | − | 600 | x | − | 300 | x | + | 600 | x | x |
= | 300 | − | 900 | x | + | 600 | x | x |
300 | − | 900 | x | + | 600 | x | x | = | 144 |
x1= | 1 5 |
x2= | 13 10 |