| ( | 6 | x | + | 2 | x | ) | ( | 2 | x | + | 6 | ) | = | 0 |
| Left side of the equation = | 6 | x | ( | 2 | x | + | 6 | ) | + | 2 | x | ( | 2 | x | + | 6 | ) |
| = | 6 | x | × | 2 | x | + | 6 | x | × | 6 | + | 2 | x | ( | 2 | x | + | 6 | ) |
| = | 12 | x | x | + | 36 | x | + | 2 | x | ( | 2 | x | + | 6 | ) |
| = | 12 | x | x | + | 36 | x | + | 2 | x | × | 2 | x | + | 2 | x | × | 6 |
| = | 12 | x | x | + | 36 | x | + | 4 | x | x | + | 12 | x |
| = | 12 | x | x | + | 48 | x | + | 4 | x | x |
| 12 | x | x | + | 48 | x | + | 4 | x | x | = | 0 |