( | 32 | − | 3 | x | ) | ( | 20 | − | 2 | x | ) | = | 240 |
方程左边 = | 32 | ( | 20 | − | 2 | x | ) | − | 3 | x | ( | 20 | − | 2 | x | ) |
= | 32 | × | 20 | − | 32 | × | 2 | x | − | 3 | x | ( | 20 | − | 2 | x | ) |
= | 640 | − | 64 | x | − | 3 | x | ( | 20 | − | 2 | x | ) |
= | 640 | − | 64 | x | − | 3 | x | × | 20 | + | 3 | x | × | 2 | x |
= | 640 | − | 64 | x | − | 60 | x | + | 6 | x | x |
= | 640 | − | 124 | x | + | 6 | x | x |
640 | − | 124 | x | + | 6 | x | x | = | 240 |
x2= | 50 3 |