| ( | 162 | − | 3 | x | ) | ( | x | − | 30 | ) | = | 0 |
| Left side of the equation = | 162 | ( | x | − | 30 | ) | − | 3 | x | ( | x | − | 30 | ) |
| = | 162 | x | − | 162 | × | 30 | − | 3 | x | ( | x | − | 30 | ) |
| = | 162 | x | − | 4860 | − | 3 | x | ( | x | − | 30 | ) |
| = | 162 | x | − | 4860 | − | 3 | x | x | + | 3 | x | × | 30 |
| = | 162 | x | − | 4860 | − | 3 | x | x | + | 90 | x |
| = | 252 | x | − | 4860 | − | 3 | x | x |
| 252 | x | − | 4860 | − | 3 | x | x | = | 0 |