( | x | − | 360 | ) | ( | 160 | + | 2 | ( | 480 | − | x | ) | ) | = | 20000 |
方程左边 = | x | ( | 160 | + | 2 | ( | 480 | − | x | ) | ) | − | 360 | ( | 160 | + | 2 | ( | 480 | − | x | ) | ) |
= | x | × | 160 | + | x | × | 2 | ( | 480 | − | x | ) | − | 360 | ( | 160 | + | 2 | ( | 480 | − | x | ) | ) |
= | 160 | x | + | x | × | 2 | × | 480 | − | x | × | 2 | x | − | 360 | ( | 160 | + | 2 | ( | 480 | − | x | ) | ) |
= | 160 | x | + | x | × | 960 | − | x | × | 2 | x | − | 360 | ( | 160 | + | 2 | ( | 480 | − | x | ) | ) |
= | 1120 | x | − | x | × | 2 | x | − | 360 | ( | 160 | + | 2 | ( | 480 | − | x | ) | ) |
= | 1120 | x | − | x | × | 2 | x | − | 360 | × | 160 | − | 360 | × | 2 | ( | 480 | − | x | ) |
= | 1120 | x | − | x | × | 2 | x | − | 57600 | − | 720 | ( | 480 | − | x | ) |
= | 1120 | x | − | x | × | 2 | x | − | 57600 | − | 720 | × | 480 | + | 720 | x |
= | 1120 | x | − | x | × | 2 | x | − | 57600 | − | 345600 | + | 720 | x |
= | 1840 | x | − | x | × | 2 | x | − | 403200 |
1840 | x | − | x | × | 2 | x | − | 403200 | = | 20000 |