| ( | x | − | 50 | ) | ( | 200 | − | 10 | ( | x | − | 60 | ) | ) | = | 2240 |
| Left side of the equation = | x | ( | 200 | − | 10 | ( | x | − | 60 | ) | ) | − | 50 | ( | 200 | − | 10 | ( | x | − | 60 | ) | ) |
| = | x | × | 200 | − | x | × | 10 | ( | x | − | 60 | ) | − | 50 | ( | 200 | − | 10 | ( | x | − | 60 | ) | ) |
| = | 200 | x | − | x | × | 10 | x | + | x | × | 10 | × | 60 | − | 50 | ( | 200 | − | 10 | ( | x | − | 60 | ) | ) |
| = | 200 | x | − | x | × | 10 | x | + | x | × | 600 | − | 50 | ( | 200 | − | 10 | ( | x | − | 60 | ) | ) |
| = | 800 | x | − | x | × | 10 | x | − | 50 | ( | 200 | − | 10 | ( | x | − | 60 | ) | ) |
| = | 800 | x | − | x | × | 10 | x | − | 50 | × | 200 | + | 50 | × | 10 | ( | x | − | 60 | ) |
| = | 800 | x | − | x | × | 10 | x | − | 10000 | + | 500 | ( | x | − | 60 | ) |
| = | 800 | x | − | x | × | 10 | x | − | 10000 | + | 500 | x | − | 500 | × | 60 |
| = | 800 | x | − | x | × | 10 | x | − | 10000 | + | 500 | x | − | 30000 |
| = | 1300 | x | − | x | × | 10 | x | − | 40000 |
| 1300 | x | − | x | × | 10 | x | − | 40000 | = | 2240 |