| 12 | ÷ | x | − | 12 | ÷ | ( | x | − | 4 | ) | = | 4 |
| 方程两边同时乘以: | x |
| 12 | − | 12 | ÷ | ( | x | − | 4 | ) | × | x | = | 4 | x |
| 方程两边同时乘以: | ( | x | − | 4 | ) |
| 12 | ( | x | − | 4 | ) | − | 12 | x | = | 4 | x | ( | x | − | 4 | ) |
| 12 | x | − | 12 | × | 4 | − | 12 | x | = | 4 | x | ( | x | − | 4 | ) |
| 12 | x | − | 12 | × | 4 | − | 12 | x | = | 4 | x | x | − | 4 | x | × | 4 |
| 12 | x | − | 48 | − | 12 | x | = | 4 | x | x | − | 16 | x |
| 0 | x | − | 48 | = | 4 | x | x | − | 16 | x |