| 4 | − | 1 | ÷ | 3 | × | a | = | 1 | ÷ | 2 | × | a | ( | 2 | − | 1 | ) |
| 方程左边 = | 4 | − | 1 3 | a |
| 4 | − | 1 3 | a | = | 1 | ÷ | 2 | × | a | ( | 2 | − | 1 | ) |
| 方程右边 = | 1 2 | a | ( | 2 | − | 1 | ) |
| 4 | − | 1 3 | a | = | 1 2 | a | ( | 2 | − | 1 | ) |
| 方程右边 = | 1 2 | a | × | 2 | − | 1 2 | a | × | 1 |
| = | 1 | a | − | 1 2 | a |
| = | 1 2 | a |
| 4 | − | 1 3 | a | = | 1 2 | a |
| - | 1 3 | a | − | 1 2 | a | = | - | 4 |
| - | 5 6 | a | = | - | 4 |
| 4 | = | 5 6 | a |
5 6 | a | = | 4 |
| a | = | 4 | ÷ | 5 6 |
| = | 4 | × | 6 5 |
| a | = | 24 5 |
| a | = | 4.8 |