| y | = | - | 1 | ÷ | 9 | × | ( | 1 | − | 4 | ) | ( | 1 | − | 4 | ) | + | 4 |
| 方程右边 = | - | 1 9 | ( | 1 | − | 4 | ) | ( | 1 | − | 4 | ) | + | 4 |
| y | = | - | 1 9 | ( | 1 | − | 4 | ) | ( | 1 | − | 4 | ) | + | 4 |
| 方程右边 = | - | 1 9 | × | 1 | ( | 1 | − | 4 | ) | + | 1 9 | × | 4 | ( | 1 | − | 4 | ) | + | 4 |
| = | - | 1 9 | ( | 1 | − | 4 | ) | + | 4 9 | ( | 1 | − | 4 | ) | + | 4 |
| = | - | 1 9 | × | 1 | + | 1 9 | × | 4 | + | 4 9 | ( | 1 | − | 4 | ) | + | 4 |
| = | - | 1 9 | + | 4 9 | + | 4 9 | ( | 1 | − | 4 | ) | + | 4 |
| = | 13 3 | + | 4 9 | ( | 1 | − | 4 | ) |
| = | 13 3 | + | 4 9 | × | 1 | − | 4 9 | × | 4 |
| = | 13 3 | + | 4 9 | − | 16 9 |
| = | 3 |
| y | = | 3 |