( | 120 | − | x | ) | ( | 64 | + | 8 5 | x | ) | = | 8800 |
方程左边 = | 120 | ( | 64 | + | 8 5 | x | ) | − | x | ( | 64 | + | 8 5 | x | ) |
= | 120 | × | 64 | + | 120 | × | 8 5 | x | − | x | ( | 64 | + | 8 5 | x | ) |
= | 7680 | + | 192 | x | − | x | ( | 64 | + | 8 5 | x | ) |
= | 7680 | + | 192 | x | − | x | × | 64 | − | x | × | 8 5 | x |
= | 7680 | + | 128 | x | − | x | × | 8 5 | x |
7680 | + | 128 | x | − | x | × | 8 5 | x | = | 8800 |