( | 180 | − | 4 | x | ) | ( | 120 | − | 6 | x | ) | = | 2 | ÷ | 3 | × | 120 | × | 180 |
方程左边 = | 180 | ( | 120 | − | 6 | x | ) | − | 4 | x | ( | 120 | − | 6 | x | ) |
= | 180 | × | 120 | − | 180 | × | 6 | x | − | 4 | x | ( | 120 | − | 6 | x | ) |
= | 21600 | − | 1080 | x | − | 4 | x | ( | 120 | − | 6 | x | ) |
= | 21600 | − | 1080 | x | − | 4 | x | × | 120 | + | 4 | x | × | 6 | x |
= | 21600 | − | 1080 | x | − | 480 | x | + | 24 | x | x |
= | 21600 | − | 1560 | x | + | 24 | x | x |
21600 | − | 1560 | x | + | 24 | x | x | = | 2 | ÷ | 3 | × | 120 | × | 180 |
方程右边 = | 14400 |
21600 | − | 1560 | x | + | 24 | x | x | = | 14400 |