| ( | 6 | × | 6 | + | y | ) | + | ( | 6 | + | 24 | + | y | ) | = | 4 | ( | 6 | + | y | ) |
| 方程左边 = | 6 | × | 6 | + | y | + | ( | 6 | + | 24 | + | y | ) |
| = | 36 | + | y | + | ( | 6 | + | 24 | + | y | ) |
| = | 36 | + | y | + | 6 | + | 24 | + | y |
| = | 66 | + | 2 | y |
| 66 | + | 2 | y | = | 4 | ( | 6 | + | y | ) |
| 方程右边 = | 4 | × | 6 | + | 4 | y |
| = | 24 | + | 4 | y |
| 66 | + | 2 | y | = | 24 | + | 4 | y |
| 2 | y | − | 4 | y | = | 24 | − | 66 |
| - | 2 | y | = | 24 | − | 66 |
| - | 2 | y | = | - | 42 |
| 42 | = | 2 | y |
| 2 | y | = | 42 |
| y | = | 42 | ÷ | 2 |
| = | 42 | × | 1 2 |
| = | 21 | × | 1 |
| y | = | 21 |