| 150 | × | 150 | − | x | x | = | 200 | × | 200 | − | ( | 250 | − | x | ) | ( | 250 | − | x | ) |
| Left side of the equation = | 22500 | − | x | x |
| 22500 | − | x | x | = | 200 | × | 200 | − | ( | 250 | − | x | ) | ( | 250 | − | x | ) |
| Right side of the equation = | 40000 | − | ( | 250 | − | x | ) | ( | 250 | − | x | ) |
| 22500 | − | x | x | = | 40000 | − | ( | 250 | − | x | ) | ( | 250 | − | x | ) |
| Right side of the equation = | 40000 | − | 250 | ( | 250 | − | x | ) | + | x | ( | 250 | − | x | ) |
| = | 40000 | − | 250 | × | 250 | + | 250 | x | + | x | ( | 250 | − | x | ) |
| = | 40000 | − | 62500 | + | 250 | x | + | x | ( | 250 | − | x | ) |
| = | - | 22500 | + | 250 | x | + | x | ( | 250 | − | x | ) |
| = | - | 22500 | + | 250 | x | + | x | × | 250 | − | x | x |
| = | - | 22500 | + | 500 | x | − | x | x |
| 22500 | − | x | x | = | - | 22500 | + | 500 | x | − | x | x |