| 7 | = | 2 | x | − | ( | 1 | + | x | ) | ÷ | ( | 1 | − | x | ) |
| 方程两边同时乘以: | ( | 1 | − | x | ) |
| 7 | ( | 1 | − | x | ) | = | 2 | x | ( | 1 | − | x | ) | − | ( | 1 | + | x | ) |
| 7 | × | 1 | − | 7 | x | = | 2 | x | ( | 1 | − | x | ) | − | ( | 1 | + | x | ) |
| 7 | × | 1 | − | 7 | x | = | 2 | x | × | 1 | − | 2 | x | x | − | ( | 1 | + | x | ) |
| 7 | − | 7 | x | = | 2 | x | − | 2 | x | x | − | ( | 1 | + | x | ) |
| 7 | − | 7 | x | = | 2 | x | − | 2 | x | x | − | 1 | − | x |
| 7 | − | 7 | x | = | 1 | x | − | 2 | x | x | − | 1 |