| ( | x | + | 3 | ) | ( | x | + | 3 | ) | = | ( | 1 | − | 2 | x | ) | ( | 1 | − | 2 | x | ) |
| 方程左边 = | x | ( | x | + | 3 | ) | + | 3 | ( | x | + | 3 | ) |
| = | x | x | + | x | × | 3 | + | 3 | ( | x | + | 3 | ) |
| = | x | x | + | 3 | x | + | 3 | x | + | 3 | × | 3 |
| = | x | x | + | 3 | x | + | 3 | x | + | 9 |
| = | x | x | + | 6 | x | + | 9 |
| x | x | + | 6 | x | + | 9 | = | ( | 1 | − | 2 | x | ) | ( | 1 | − | 2 | x | ) |
| 方程右边 = | 1 | ( | 1 | − | 2 | x | ) | − | 2 | x | ( | 1 | − | 2 | x | ) |
| = | 1 | × | 1 | − | 1 | × | 2 | x | − | 2 | x | ( | 1 | − | 2 | x | ) |
| = | 1 | − | 2 | x | − | 2 | x | ( | 1 | − | 2 | x | ) |
| = | 1 | − | 2 | x | − | 2 | x | × | 1 | + | 2 | x | × | 2 | x |
| = | 1 | − | 2 | x | − | 2 | x | + | 4 | x | x |
| = | 1 | − | 4 | x | + | 4 | x | x |
| x | x | + | 6 | x | + | 9 | = | 1 | − | 4 | x | + | 4 | x | x |
| x1= | - | 2 3 |
| x2=4 |