| ( | 1 | − | y | ÷ | 3 | ) | − | y | = | 3 | − | ( | y | + | 2 | ÷ | 2 | ) |
| 方程左边 = | 1 | − | y | ÷ | 3 | − | y |
| = | 1 | − | 4 3 | y |
| 1 | − | 4 3 | y | = | 3 | − | ( | y | + | 2 | ÷ | 2 | ) |
| 方程右边 = | 3 | − | y | − | 2 | ÷ | 2 |
| = | 3 | − | y | − | 1 |
| = | 2 | − | y |
| 1 | − | 4 3 | y | = | 2 | − | y |
| - | 4 3 | y | + | y | = | 2 | − | 1 |
| - | 1 3 | y | = | 2 | − | 1 |
| - | 1 3 | y | = | 1 |
| - | 1 | = | 1 3 | y |
1 3 | y | = | - | 1 |
| y | = | - | 1 | ÷ | 1 3 |
| = | - | 1 | × | 3 |
| y | = | - | 3 |