| ( | 6 | ÷ | 5 | ) | x | = | ( | 120 | ÷ | x | ) | + | ( | 6 | x | − | 120 | ) | x | ( | 4 | ÷ | 5 | ) | x | + | 20 |
| 6 | ÷ | 5 | × | x | = | ( | 120 | ÷ | x | ) | + | ( | 6 | x | − | 120 | ) | x | ( | 4 | ÷ | 5 | ) | x | + | 20 |
| 6 | ÷ | 5 | × | x | = | 120 | ÷ | x | + | ( | 6 | x | − | 120 | ) | x | ( | 4 | ÷ | 5 | ) | x | + | 20 |
6 5 | x | = | 120 | ÷ | x | + | ( | 6 | x | − | 120 | ) | x | ( | 4 | ÷ | 5 | ) | x | + | 20 |
| 方程两边同时乘以: | x |
6 5 | x | x | = | 120 | + | ( | 6 | x | − | 120 | ) | x | ( | 4 | ÷ | 5 | ) | x | x | + | 20 | x |
6 5 | x | x | = | 120 | + | 6 | x | x | ( | 4 | ÷ | 5 | ) | x | x | − | 120 | x | ( | 4 | ÷ | 5 | ) | x | x |
6 5 | x | x | = | 120 | + | 6 | x | x | × | 4 | ÷ | 5 | × | x | x | − | 120 | x | ( | 4 | ÷ | 5 | ) | x |
6 5 | x | x | = | 120 | + | 24 5 | x | x | x | x | − | 120 | x | ( | 4 | ÷ | 5 | ) | x | x | + | 20 |
6 5 | x | x | = | 120 | + | 24 5 | x | x | x | x | − | 120 | x | × | 4 | ÷ | 5 | × | x | x |
6 5 | x | x | = | 120 | + | 24 5 | x | x | x | x | − | 96 | x | x | x | + | 20 | x |