| 2 | ( | 2 | x | − | 1 | ) | ( | x | + | 6 | ) | − | 3 | ( | x | − | 3 | ) | ( | x | + | 6 | ) | = | 0 |
| 方程左边 = | 2 | × | 2 | x | ( | x | + | 6 | ) | − | 2 | × | 1 | ( | x | + | 6 | ) | − | 3 | ( | x | − | 3 | ) | ( | x | + | 6 | ) |
| = | 4 | x | ( | x | + | 6 | ) | − | 2 | ( | x | + | 6 | ) | − | 3 | ( | x | − | 3 | ) | ( | x | + | 6 | ) |
| = | 4 | x | x | + | 4 | x | × | 6 | − | 2 | ( | x | + | 6 | ) | − | 3 | ( | x | − | 3 | ) | ( | x | + | 6 | ) |
| = | 4 | x | x | + | 24 | x | − | 2 | ( | x | + | 6 | ) | − | 3 | ( | x | − | 3 | ) | ( | x | + | 6 | ) |
| = | 4 | x | x | + | 24 | x | − | 2 | x | − | 2 | × | 6 | − | 3 | ( | x | − | 3 | ) | ( | x | + | 6 | ) |
| = | 4 | x | x | + | 24 | x | − | 2 | x | − | 12 | − | 3 | ( | x | − | 3 | ) | ( | x | + | 6 | ) |
| = | 4 | x | x | + | 22 | x | − | 12 | − | 3 | ( | x | − | 3 | ) | ( | x | + | 6 | ) |
| = | 4 | x | x | + | 22 | x | − | 12 | − | 3 | x | ( | x | + | 6 | ) | + | 3 | × | 3 | ( | x | + | 6 | ) |
| = | 4 | x | x | + | 22 | x | − | 12 | − | 3 | x | ( | x | + | 6 | ) | + | 9 | ( | x | + | 6 | ) |
| = | 4 | x | x | + | 22 | x | − | 12 | − | 3 | x | x | − | 3 | x | × | 6 |
| = | 4 | x | x | + | 22 | x | − | 12 | − | 3 | x | x | − | 18 | x | + | 9 |
| = | 4 | x | x | + | 4 | x | − | 12 | − | 3 | x | x | + | 9 | ( | x | + | 6 | ) |
| = | 4 | x | x | + | 4 | x | − | 12 | − | 3 | x | x | + | 9 | x | + | 9 |
| = | 4 | x | x | + | 4 | x | − | 12 | − | 3 | x | x | + | 9 | x | + | 54 |
| = | 4 | x | x | + | 13 | x | + | 42 | − | 3 | x | x |
| 4 | x | x | + | 13 | x | + | 42 | − | 3 | x | x | = | 0 |