| ( | - | 1 | − | a | ) | ( | 3 | − | a | ) | ( | 2 | − | a | ) | = | 0 |
| Left side of the equation = | - | 1 | ( | 3 | − | a | ) | ( | 2 | − | a | ) | − | a | ( | 3 | − | a | ) | ( | 2 | − | a | ) |
| = | - | 1 | × | 3 | ( | 2 | − | a | ) | + | 1 | a | ( | 2 | − | a | ) | − | a | ( | 3 | − | a | ) | ( | 2 | − | a | ) |
| = | - | 3 | ( | 2 | − | a | ) | + | 1 | a | ( | 2 | − | a | ) | − | a | ( | 3 | − | a | ) | ( | 2 | − | a | ) |
| = | - | 3 | × | 2 | + | 3 | a | + | 1 | a | ( | 2 | − | a | ) | − | a | ( | 3 | − | a | ) | ( | 2 | − | a | ) |
| = | - | 6 | + | 3 | a | + | 1 | a | ( | 2 | − | a | ) | − | a | ( | 3 | − | a | ) | ( | 2 | − | a | ) |
| = | - | 6 | + | 3 | a | + | 1 | a | × | 2 | − | 1 | a | a | − | a | ( | 3 | − | a | ) | ( | 2 | − | a | ) |
| = | - | 6 | + | 3 | a | + | 2 | a | − | 1 | a | a | − | a | ( | 3 | − | a | ) | ( | 2 | − | a | ) |
| = | - | 6 | + | 5 | a | − | 1 | a | a | − | a | ( | 3 | − | a | ) | ( | 2 | − | a | ) |
| = | - | 6 | + | 5 | a | − | 1 | a | a | − | a | × | 3 | ( | 2 | − | a | ) | + | a | a | ( | 2 | − | a | ) |
| = | - | 6 | + | 5 | a | − | 1 | a | a | − | a | × | 3 | × | 2 | + | a | × | 3 | a |
| = | - | 6 | + | 5 | a | − | 1 | a | a | − | a | × | 6 | + | a | × | 3 | a | + | a |
| = | - | 6 | − | 1 | a | − | 1 | a | a | + | a | × | 3 | a | + | a | a | ( | 2 | − | a | ) |
| = | - | 6 | − | 1 | a | − | 1 | a | a | + | a | × | 3 | a | + | a | a | × | 2 |
| - | 6 | − | 1 | a | − | 1 | a | a | + | a | × | 3 | a | + | a | a | × | 2 | = | 0 |