( | x | − | 40 | ) | ( | 500 | − | ( | x | − | 50 | ) | ÷ | 1 10 | ) | = | 8000 |
方程左边 = | x | ( | 500 | − | ( | x | − | 50 | ) | ÷ | 1 10 | ) | − | 40 | ( | 500 | − | ( | x | − | 50 | ) | ÷ | 1 10 | ) |
= | x | × | 500 | − | x | ( | x | − | 50 | ) | ÷ | 1 10 | − | 40 | ( | 500 | − | ( | x | − | 50 | ) | ÷ | 1 10 | ) |
= | 500 | x | − | x | x | × | 10 | + | x | × | 50 | × | 10 | − | 40 | ( | 500 | − | ( | x | − | 50 | ) | ÷ | 1 10 | ) |
= | 500 | x | − | x | x | × | 10 | + | x | × | 500 | − | 40 | ( | 500 | − | ( | x | − | 50 | ) | ÷ | 1 10 | ) |
= | 1000 | x | − | x | x | × | 10 | − | 40 | ( | 500 | − | ( | x | − | 50 | ) | ÷ | 1 10 | ) |
= | 1000 | x | − | x | x | × | 10 | − | 40 | × | 500 | + | 40 | ( | x | − | 50 | ) | ÷ | 1 10 |
= | 1000 | x | − | x | x | × | 10 | − | 20000 | + | 400 | ( | x | − | 50 | ) |
= | 1000 | x | − | x | x | × | 10 | − | 20000 | + | 400 | x | − | 400 | × | 50 |
= | 1000 | x | − | x | x | × | 10 | − | 20000 | + | 400 | x | − | 20000 |
= | 1400 | x | − | x | x | × | 10 | − | 40000 |
1400 | x | − | x | x | × | 10 | − | 40000 | = | 8000 |