( | 40 | − | 1 2 | x | ) | ( | 48 | + | 4 | x | ) | = | 512 |
方程左边 = | 40 | ( | 48 | + | 4 | x | ) | − | 1 2 | x | ( | 48 | + | 4 | x | ) |
= | 40 | × | 48 | + | 40 | × | 4 | x | − | 1 2 | x | ( | 48 | + | 4 | x | ) |
= | 1920 | + | 160 | x | − | 1 2 | x | ( | 48 | + | 4 | x | ) |
= | 1920 | + | 160 | x | − | 1 2 | x | × | 48 | − | 1 2 | x | × | 4 | x |
= | 1920 | + | 160 | x | − | 24 | x | − | 2 | x | x |
= | 1920 | + | 136 | x | − | 2 | x | x |
1920 | + | 136 | x | − | 2 | x | x | = | 512 |