| ( | 4 | − | 8 | ÷ | a | ) | ( | a | − | 3 | ) | = | 4 |
| 4 | ( | a | − | 3 | ) | − | 8 | ÷ | a | × | ( | a | − | 3 | ) | = | 4 |
| 方程两边同时乘以: | a |
| 4 | ( | a | − | 3 | ) | a | − | 8 | ( | a | − | 3 | ) | = | 4 | a |
| 4 | a | a | − | 4 | × | 3 | a | − | 8 | ( | a | − | 3 | ) | = | 4 | a |
| 4 | a | a | − | 12 | a | − | 8 | ( | a | − | 3 | ) | = | 4 | a |
| 4 | a | a | − | 12 | a | − | 8 | a | + | 8 | × | 3 | = | 4 | a |
| 4 | a | a | − | 12 | a | − | 8 | a | + | 24 | = | 4 | a |
| 4 | a | a | − | 20 | a | + | 24 | = | 4 | a |