| ( | - | 2 | − | x | ) | ( | 2 | − | x | ) | ( | 1 | − | x | ) | − | 2 | ( | - | 2 | − | x | ) | = | 0 |
| Left side of the equation = | - | 2 | ( | 2 | − | x | ) | ( | 1 | − | x | ) | − | x | ( | 2 | − | x | ) | ( | 1 | − | x | ) | − | 2 | ( | - | 2 | − | x | ) |
| = | - | 2 | × | 2 | ( | 1 | − | x | ) | + | 2 | x | ( | 1 | − | x | ) | − | x | ( | 2 | − | x | ) | ( | 1 | − | x | ) | − | 2 | ( | - | 2 | − | x | ) |
| = | - | 4 | ( | 1 | − | x | ) | + | 2 | x | ( | 1 | − | x | ) | − | x | ( | 2 | − | x | ) | ( | 1 | − | x | ) | − | 2 | ( | - | 2 | − | x | ) |
| = | - | 4 | × | 1 | + | 4 | x | + | 2 | x | ( | 1 | − | x | ) | − | x | ( | 2 | − | x | ) | ( | 1 | − | x | ) | − | 2 | ( | - | 2 | − | x | ) |
| = | - | 4 | + | 4 | x | + | 2 | x | ( | 1 | − | x | ) | − | x | ( | 2 | − | x | ) | ( | 1 | − | x | ) | − | 2 | ( | - | 2 | − | x | ) |
| = | - | 4 | + | 4 | x | + | 2 | x | × | 1 | − | 2 | x | x | − | x | ( | 2 | − | x | ) | ( | 1 | − | x | ) |
| = | - | 4 | + | 4 | x | + | 2 | x | − | 2 | x | x | − | x | ( | 2 | − | x | ) | ( | 1 | − | x | ) | − | 2 |
| = | - | 4 | + | 6 | x | − | 2 | x | x | − | x | ( | 2 | − | x | ) | ( | 1 | − | x | ) | − | 2 | ( | - | 2 | − | x | ) |
| = | - | 4 | + | 6 | x | − | 2 | x | x | − | x | × | 2 | ( | 1 | − | x | ) | + | x | x | ( | 1 | − | x | ) |
| = | - | 4 | + | 6 | x | − | 2 | x | x | − | x | × | 2 | × | 1 | + | x | × | 2 | x |
| = | - | 4 | + | 6 | x | − | 2 | x | x | − | x | × | 2 | + | x | × | 2 | x | + | x |
| = | - | 4 | + | 4 | x | − | 2 | x | x | + | x | × | 2 | x | + | x | x | ( | 1 | − | x | ) |
| = | - | 4 | + | 4 | x | − | 2 | x | x | + | x | × | 2 | x | + | x | x | × | 1 |
| = | - | 4 | + | 4 | x | − | 2 | x | x | + | x | × | 2 | x | + | x | x | × | 1 |
| = | - | 4 | + | 4 | x | − | 2 | x | x | + | x | × | 2 | x | + | x | x | × | 1 |
| = | - | 0 | + | 6 | x | − | 2 | x | x | + | x | × | 2 | x | + | x | x | × | 1 |
| - | 0 | + | 6 | x | − | 2 | x | x | + | x | × | 2 | x | + | x | x | × | 1 | = | 0 |