( | 300 | + | 5 | ( | 200 | − | x | ) | ) | x | − | 100 | ( | 300 | + | 5 | ( | 200 | − | x | ) | ) | = | 32000 |
方程左边 = | 300 | x | + | 5 | ( | 200 | − | x | ) | x | − | 100 | ( | 300 | + | 5 | ( | 200 | − | x | ) | ) |
= | 300 | x | + | 5 | × | 200 | x | − | 5 | x | x | − | 100 | ( | 300 | + | 5 | ( | 200 | − | x | ) | ) |
= | 300 | x | + | 1000 | x | − | 5 | x | x | − | 100 | ( | 300 | + | 5 | ( | 200 | − | x | ) | ) |
= | 1300 | x | − | 5 | x | x | − | 100 | ( | 300 | + | 5 | ( | 200 | − | x | ) | ) |
= | 1300 | x | − | 5 | x | x | − | 100 | × | 300 | − | 100 | × | 5 | ( | 200 | − | x | ) |
= | 1300 | x | − | 5 | x | x | − | 30000 | − | 500 | ( | 200 | − | x | ) |
= | 1300 | x | − | 5 | x | x | − | 30000 | − | 500 | × | 200 | + | 500 | x |
= | 1300 | x | − | 5 | x | x | − | 30000 | − | 100000 | + | 500 | x |
= | 1800 | x | − | 5 | x | x | − | 130000 |
1800 | x | − | 5 | x | x | − | 130000 | = | 32000 |