| - | 2 | k | − | 6 | = | ( | 2 | k | − | 6 | ) | ( | 4 | − | k | ) |
| Right side of the equation = | 2 | k | ( | 4 | − | k | ) | − | 6 | ( | 4 | − | k | ) |
| = | 2 | k | × | 4 | − | 2 | k | k | − | 6 | ( | 4 | − | k | ) |
| = | 8 | k | − | 2 | k | k | − | 6 | ( | 4 | − | k | ) |
| = | 8 | k | − | 2 | k | k | − | 6 | × | 4 | + | 6 | k |
| = | 8 | k | − | 2 | k | k | − | 24 | + | 6 | k |
| = | 14 | k | − | 2 | k | k | − | 24 |
| - | 2 | k | − | 6 | = | 14 | k | − | 2 | k | k | − | 24 |