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