| ( | ( | 600 | ) | ÷ | ( | x | ) | ) | − | 50 | = | ( | ( | 600 | ) | ÷ | ( | x | + | 1 5 | x | ) | ) |
| ( | 600 | ) | ÷ | ( | x | ) | − | 50 | = | ( | ( | 600 | ) | ÷ | ( | x | + | 1 5 | x | ) | ) |
| ( | 600 | ) | ÷ | ( | x | ) | − | 50 | = | ( | 600 | ) | ÷ | ( | x | + | 1 5 | x | ) |
| 方程两边同时乘以: | ( | x | ) | , | ( | x | + | 1 5 | x | ) |
| ( | 600 | ) | ( | x | + | 1 5 | x | ) | − | 50 | ( | x | ) | ( | x | + | 1 5 | x | ) | = | ( | 600 | ) | ( | x | ) |
| 600 | ( | x | + | 1 5 | x | ) | − | 50 | ( | x | ) | ( | x | + | 1 5 | x | ) | = | ( | 600 | ) | ( | x | ) |
| 600 | ( | x | + | 1 5 | x | ) | − | 50 | ( | x | ) | ( | x | + | 1 5 | x | ) | = | 600 | ( | x | ) |
| 600 | x | + | 600 | × | 1 5 | x | − | 50 | ( | x | ) | ( | x | + | 1 5 | x | ) | = | 600 | ( | x | ) |
| 600 | x | + | 600 | × | 1 5 | x | − | 50 | ( | x | ) | ( | x | + | 1 5 | x | ) | = | 600 | x |
| 600 | x | + | 120 | x | − | 50 | ( | x | ) | ( | x | + | 1 5 | x | ) | = | 600 | x |
| 720 | x | − | 50 | ( | x | ) | ( | x | + | 1 5 | x | ) | = | 600 | x |
| 720 | x | − | 50 | x | ( | x | + | 1 5 | x | ) | = | 600 | x |
| 720 | x | − | 50 | x | x | − | 50 | x | × | 1 5 | x | = | 600 | x |
| 720 | x | − | 50 | x | x | − | 10 | x | x | = | 600 | x |