| 2 | a | + | 2 | a | − | 1 | − | ( | 3 | ( | a | − | 1 | ) | + | a | + | 2 | ) | = | 0 |
| Left side of the equation = | 4 | a | − | 1 | − | ( | 3 | ( | a | − | 1 | ) | + | a | + | 2 | ) |
| 4 | a | − | 1 | − | ( | 3 | ( | a | − | 1 | ) | + | a | + | 2 | ) | = | 0 |
| Left side of the equation = | 4 | a | − | 1 | − | 3 | ( | a | − | 1 | ) | − | a | − | 2 |
| = | 3 | a | − | 3 | − | 3 | ( | a | − | 1 | ) |
| = | 3 | a | − | 3 | − | 3 | a | + | 3 | × | 1 |
| = | 3 | a | − | 3 | − | 3 | a | + | 3 |
| = | 0 | a | − | 0 |
| 0 | a | − | 0 | = | 0 |
| = | 0 | + | 0 |