| ( | x | − | 40 | ) | ( | 500 | − | 10 | × | 2 | ÷ | x | − | 50 | ) | = | 8000 |
| x | ( | 500 | − | 10 | × | 2 | ÷ | x | − | 50 | ) | − | 40 | ( | 500 | − | 10 | × | 2 | ÷ | x | − | 50 | ) | = | 8000 |
| x | × | 500 | − | x | × | 10 | × | 2 | ÷ | x | − | x | × | 50 | − | 40 | ( | 500 | − | 10 | × | 2 | ÷ | x | − | 50 | ) | = | 8000 |
| x | × | 500 | − | x | × | 20 | ÷ | x | − | x | × | 50 | − | 40 | ( | 500 | − | 10 | × | 2 | ÷ | x | − | 50 | ) | = | 8000 |
| 450 | x | − | x | × | 20 | ÷ | x | − | 40 | ( | 500 | − | 10 | × | 2 | ÷ | x | − | 50 | ) | = | 8000 |
| 450 | x | − | 1 | × | 20 | ÷ | 1 | − | 40 | × | 500 | + | 40 | × | 10 | × | 2 | ÷ | x | + | 40 | = | 8000 |
| 450 | x | − | 20 | − | 20000 | + | 800 | ÷ | x | + | 2000 | = | 8000 |
| 450 | x | − | 18020 | + | 800 | ÷ | x | = | 8000 |
| 方程两边同时乘以: | x |
| 450 | x | x | − | 18020 | x | + | 800 | = | 8000 | x |