| x | − | ( | x | − | 50 | ) | ( | x | − | 50 | ) | = | 50 |
| Left side of the equation = | x | − | x | ( | x | − | 50 | ) | + | 50 | ( | x | − | 50 | ) |
| = | x | − | x | x | + | x | × | 50 | + | 50 | ( | x | − | 50 | ) |
| = | 51 | x | − | x | x | + | 50 | ( | x | − | 50 | ) |
| = | 51 | x | − | x | x | + | 50 | x | − | 50 | × | 50 |
| = | 51 | x | − | x | x | + | 50 | x | − | 2500 |
| = | 101 | x | − | x | x | − | 2500 |
| 101 | x | − | x | x | − | 2500 | = | 50 |