| ( | 3 | − | x | ) | ÷ | ( | x | − | 4 | ) | = | 1 | ÷ | ( | 4 | − | x | ) | − | 2 |
| 方程两边同时乘以: | ( | x | − | 4 | ) | , | ( | 4 | − | x | ) |
| ( | 3 | − | x | ) | ( | 4 | − | x | ) | = | 1 | ( | x | − | 4 | ) | − | 2 | ( | x | − | 4 | ) | ( | 4 | − | x | ) |
| 3 | ( | 4 | − | x | ) | − | x | ( | 4 | − | x | ) | = | 1 | ( | x | − | 4 | ) | − | 2 | ( | x | − | 4 | ) | ( | 4 | − | x | ) |
| 3 | ( | 4 | − | x | ) | − | x | ( | 4 | − | x | ) | = | 1 | x | − | 1 | × | 4 | − | 2 | ( | x | − | 4 | ) | ( | 4 | − | x | ) |
| 3 | ( | 4 | − | x | ) | − | x | ( | 4 | − | x | ) | = | 1 | x | − | 4 | − | 2 | ( | x | − | 4 | ) | ( | 4 | − | x | ) |
| 3 | × | 4 | − | 3 | x | − | x | ( | 4 | − | x | ) | = | 1 | x | − | 4 | − | 2 | ( | x | − | 4 | ) | ( | 4 | − | x | ) |
| 3 | × | 4 | − | 3 | x | − | x | ( | 4 | − | x | ) | = | 1 | x | − | 4 | − | 2 | x | ( | 4 | − | x | ) | + | 2 | × | 4 | ( | 4 | − | x | ) |
| 12 | − | 3 | x | − | x | ( | 4 | − | x | ) | = | 1 | x | − | 4 | − | 2 | x | ( | 4 | − | x | ) | + | 8 | ( | 4 | − | x | ) |
| 12 | − | 3 | x | − | x | × | 4 | + | x | x | = | 1 | x | − | 4 | − | 2 | x | ( | 4 | − | x | ) | + | 8 | ( | 4 | − | x | ) |
| 12 | − | 3 | x | − | x | × | 4 | + | x | x | = | 1 | x | − | 4 | − | 2 | x | × | 4 | + | 2 | x | x | + | 8 | ( | 4 | − | x | ) |
| 12 | − | 3 | x | − | x | × | 4 | + | x | x | = | 1 | x | − | 4 | − | 8 | x | + | 2 | x | x | + | 8 | ( | 4 | − | x | ) |
| 12 | − | 7 | x | + | x | x | = | - | 7 | x | − | 4 | + | 2 | x | x | + | 8 | ( | 4 | − | x | ) |
| 12 | − | 7 | x | + | x | x | = | - | 7 | x | − | 4 | + | 2 | x | x | + | 8 | × | 4 | − | 8 | x |
| 12 | − | 7 | x | + | x | x | = | - | 7 | x | − | 4 | + | 2 | x | x | + | 32 | − | 8 | x |
| 12 | − | 7 | x | + | x | x | = | - | 15 | x | + | 28 | + | 2 | x | x |