| ( | 10 | x | + | 50 | ) | ( | x | − | 3 | ) | = | 0 |
| Left side of the equation = | 10 | x | ( | x | − | 3 | ) | + | 50 | ( | x | − | 3 | ) |
| = | 10 | x | x | − | 10 | x | × | 3 | + | 50 | ( | x | − | 3 | ) |
| = | 10 | x | x | − | 30 | x | + | 50 | ( | x | − | 3 | ) |
| = | 10 | x | x | − | 30 | x | + | 50 | x | − | 50 | × | 3 |
| = | 10 | x | x | − | 30 | x | + | 50 | x | − | 150 |
| = | 10 | x | x | + | 20 | x | − | 150 |
| 10 | x | x | + | 20 | x | − | 150 | = | 0 |