( | 1000 | − | 2 | x | ) | ( | 100 | + | x | ) | = | 1152 |
方程左边 = | 1000 | ( | 100 | + | x | ) | − | 2 | x | ( | 100 | + | x | ) |
= | 1000 | × | 100 | + | 1000 | x | − | 2 | x | ( | 100 | + | x | ) |
= | 100000 | + | 1000 | x | − | 2 | x | ( | 100 | + | x | ) |
= | 100000 | + | 1000 | x | − | 2 | x | × | 100 | − | 2 | x | x |
= | 100000 | + | 1000 | x | − | 200 | x | − | 2 | x | x |
= | 100000 | + | 800 | x | − | 2 | x | x |
100000 | + | 800 | x | − | 2 | x | x | = | 1152 |