| 3 | x | ( | x | − | 3 | ) | = | 2 | ( | x | − | 1 | ) | ( | x | + | 1 | ) |
| Left side of the equation = | 3 | x | x | − | 3 | x | × | 3 |
| = | 3 | x | x | − | 9 | x |
| 3 | x | x | − | 9 | x | = | 2 | ( | x | − | 1 | ) | ( | x | + | 1 | ) |
| Right side of the equation = | 2 | x | ( | x | + | 1 | ) | − | 2 | × | 1 | ( | x | + | 1 | ) |
| = | 2 | x | ( | x | + | 1 | ) | − | 2 | ( | x | + | 1 | ) |
| = | 2 | x | x | + | 2 | x | × | 1 | − | 2 | ( | x | + | 1 | ) |
| = | 2 | x | x | + | 2 | x | − | 2 | ( | x | + | 1 | ) |
| = | 2 | x | x | + | 2 | x | − | 2 | x | − | 2 | × | 1 |
| = | 2 | x | x | + | 2 | x | − | 2 | x | − | 2 |
| = | 2 | x | x | + | 0 | x | − | 2 |
| 3 | x | x | − | 9 | x | = | 2 | x | x | − | 2 |