( | 40 | − | x | ) | ( | 80 | − | 4 | x | ) | + | ( | 40 | − | x | ) | ( | 4 | x | + | 8 | ) | = | 17280 |
方程左边 = | 40 | ( | 80 | − | 4 | x | ) | − | x | ( | 80 | − | 4 | x | ) | + | ( | 40 | − | x | ) | ( | 4 | x | + | 8 | ) |
= | 40 | × | 80 | − | 40 | × | 4 | x | − | x | ( | 80 | − | 4 | x | ) | + | ( | 40 | − | x | ) | ( | 4 | x | + | 8 | ) |
= | 3200 | − | 160 | x | − | x | ( | 80 | − | 4 | x | ) | + | ( | 40 | − | x | ) | ( | 4 | x | + | 8 | ) |
= | 3200 | − | 160 | x | − | x | × | 80 | + | x | × | 4 | x | + | ( | 40 | − | x | ) | ( | 4 | x | + | 8 | ) |
= | 3200 | − | 240 | x | + | x | × | 4 | x | + | ( | 40 | − | x | ) | ( | 4 | x | + | 8 | ) |
= | 3200 | − | 240 | x | + | x | × | 4 | x | + | 40 | ( | 4 | x | + | 8 | ) | − | x | ( | 4 | x | + | 8 | ) |
= | 3200 | − | 240 | x | + | x | × | 4 | x | + | 40 | × | 4 | x | + | 40 | × | 8 | − | x |
= | 3200 | − | 240 | x | + | x | × | 4 | x | + | 160 | x | + | 320 | − | x | ( | 4 | x | + | 8 | ) |
= | 3520 | − | 80 | x | + | x | × | 4 | x | − | x | ( | 4 | x | + | 8 | ) |
= | 3520 | − | 80 | x | + | x | × | 4 | x | − | x | × | 4 | x | − | x | × | 8 |
= | 3520 | − | 88 | x | + | x | × | 4 | x | − | x | × | 4 | x |
3520 | − | 88 | x | + | x | × | 4 | x | − | x | × | 4 | x | = | 17280 |
x= | - | 1720 11 |