| ( | - | 2 | a | × | 2 | ) | × | 3 | − | ( | 3 | a | ) | × | 2 | ( | - | a | × | 2 | ) | = | 0 |
| Left side of the equation = | - | 2 | a | × | 2 | × | 3 | − | ( | 3 | a | ) | × | 2 | ( | - | a | × | 2 | ) |
| = | - | 12 | a | − | ( | 3 | a | ) | × | 2 | ( | - | a | × | 2 | ) |
| = | - | 12 | a | − | 3 | a | × | 2 | ( | - | a | × | 2 | ) |
| = | - | 12 | a | − | 6 | a | ( | - | a | × | 2 | ) |
| = | - | 12 | a | + | 6 | a | a | × | 2 |
| = | - | 12 | a | + | 12 | a | a |
| - | 12 | a | + | 12 | a | a | = | 0 |