| ( | 6 | − | 2 | x | ) | ( | 18 | − | 3 | x | ) | = | 0 |
| Left side of the equation = | 6 | ( | 18 | − | 3 | x | ) | − | 2 | x | ( | 18 | − | 3 | x | ) |
| = | 6 | × | 18 | − | 6 | × | 3 | x | − | 2 | x | ( | 18 | − | 3 | x | ) |
| = | 108 | − | 18 | x | − | 2 | x | ( | 18 | − | 3 | x | ) |
| = | 108 | − | 18 | x | − | 2 | x | × | 18 | + | 2 | x | × | 3 | x |
| = | 108 | − | 18 | x | − | 36 | x | + | 6 | x | x |
| = | 108 | − | 54 | x | + | 6 | x | x |
| 108 | − | 54 | x | + | 6 | x | x | = | 0 |