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