| - | 1 | ÷ | 12 | × | ( | X | − | 10 | ) | ( | X | + | 4 | ) | = | 0 |
| 方程左边 = | - | 1 12 | ( | X | − | 10 | ) | ( | X | + | 4 | ) |
| - | 1 12 | ( | X | − | 10 | ) | ( | X | + | 4 | ) | = | 0 |
| 方程左边 = | - | 1 12 | X | ( | X | + | 4 | ) | + | 1 12 | × | 10 | ( | X | + | 4 | ) |
| = | - | 1 12 | X | ( | X | + | 4 | ) | + | 5 6 | ( | X | + | 4 | ) |
| = | - | 1 12 | X | X | − | 1 12 | X | × | 4 | + | 5 6 | ( | X | + | 4 | ) |
| = | - | 1 12 | X | X | − | 1 3 | X | + | 5 6 | ( | X | + | 4 | ) |
| = | - | 1 12 | X | X | − | 1 3 | X | + | 5 6 | X | + | 5 6 | × | 4 |
| = | - | 1 12 | X | X | − | 1 3 | X | + | 5 6 | X | + | 10 3 |
| = | - | 1 12 | X | X | + | 1 2 | X | + | 10 3 |
| - | 1 12 | X | X | + | 1 2 | X | + | 10 3 | = | 0 |