( | 16 | − | 3 | x | ) | ( | 160 | + | 120 | x | ) | = | 3640 |
方程左边 = | 16 | ( | 160 | + | 120 | x | ) | − | 3 | x | ( | 160 | + | 120 | x | ) |
= | 16 | × | 160 | + | 16 | × | 120 | x | − | 3 | x | ( | 160 | + | 120 | x | ) |
= | 2560 | + | 1920 | x | − | 3 | x | ( | 160 | + | 120 | x | ) |
= | 2560 | + | 1920 | x | − | 3 | x | × | 160 | − | 3 | x | × | 120 | x |
= | 2560 | + | 1920 | x | − | 480 | x | − | 360 | x | x |
= | 2560 | + | 1440 | x | − | 360 | x | x |
2560 | + | 1440 | x | − | 360 | x | x | = | 3640 |