| ( | 2 | − | x | ) | − | ( | 1 | − | x | ) | ( | - | x | ) | + | 4 | x | − | 4 | ( | 2 | − | x | ) | = | 0 |
| Left side of the equation = | 2 | − | x | − | ( | 1 | − | x | ) | ( | - | x | ) | + | 4 | x | − | 4 | ( | 2 | − | x | ) |
| = | 2 | + | 3 | x | − | ( | 1 | − | x | ) | ( | - | x | ) | − | 4 | ( | 2 | − | x | ) |
| = | 2 | + | 3 | x | − | 1 | ( | - | x | ) | + | x | ( | - | x | ) | − | 4 | ( | 2 | − | x | ) |
| = | 2 | + | 3 | x | + | 1 | x | + | x | ( | - | x | ) | − | 4 | ( | 2 | − | x | ) |
| = | 2 | + | 4 | x | + | x | ( | - | x | ) | − | 4 | ( | 2 | − | x | ) |
| = | 2 | + | 4 | x | − | x | x | − | 4 | ( | 2 | − | x | ) |
| = | 2 | + | 4 | x | − | x | x | − | 4 | × | 2 | + | 4 | x |
| = | 2 | + | 4 | x | − | x | x | − | 8 | + | 4 | x |
| = | - | 6 | + | 8 | x | − | x | x |
| - | 6 | + | 8 | x | − | x | x | = | 0 |