| ( | 4 | y | + | 20 | ) | ÷ | 4 | = | ( | 6 | y | − | 20 | ) | ÷ | 5 | − | 2 |
| 方程左边 = | 4 | y | × | 1 4 | + | 20 | × | 1 4 |
| = | 1 | y | + | 5 |
| 1 | y | + | 5 | = | ( | 6 | y | − | 20 | ) | ÷ | 5 | − | 2 |
| 方程右边 = | 6 | y | × | 1 5 | − | 20 | × | 1 5 | − | 2 |
| = | 6 5 | y | − | 4 | − | 2 |
| = | 6 5 | y | − | 6 |
| 1 | y | + | 5 | = | 6 5 | y | − | 6 |
| 1 | y | − | 6 5 | y | = | - | 6 | − | 5 |
| - | 1 5 | y | = | - | 6 | − | 5 |
| - | 1 5 | y | = | - | 11 |
| 11 | = | 1 5 | y |
1 5 | y | = | 11 |
| y | = | 11 | ÷ | 1 5 |
| = | 11 | × | 5 |
| y | = | 55 |