| ( | 160 | + | 10 | x | ) | ( | 80 | − | x | ) | − | 50 | ( | 160 | + | 10 | x | ) | = | 5280 |
| Left side of the equation = | 160 | ( | 80 | − | x | ) | + | 10 | x | ( | 80 | − | x | ) | − | 50 | ( | 160 | + | 10 | x | ) |
| = | 160 | × | 80 | − | 160 | x | + | 10 | x | ( | 80 | − | x | ) | − | 50 | ( | 160 | + | 10 | x | ) |
| = | 12800 | − | 160 | x | + | 10 | x | ( | 80 | − | x | ) | − | 50 | ( | 160 | + | 10 | x | ) |
| = | 12800 | − | 160 | x | + | 10 | x | × | 80 | − | 10 | x | x | − | 50 | ( | 160 | + | 10 | x | ) |
| = | 12800 | − | 160 | x | + | 800 | x | − | 10 | x | x | − | 50 | ( | 160 | + | 10 | x | ) |
| = | 12800 | + | 640 | x | − | 10 | x | x | − | 50 | ( | 160 | + | 10 | x | ) |
| = | 12800 | + | 640 | x | − | 10 | x | x | − | 50 | × | 160 | − | 50 | × | 10 | x |
| = | 12800 | + | 640 | x | − | 10 | x | x | − | 8000 | − | 500 | x |
| = | 4800 | + | 140 | x | − | 10 | x | x |
| 4800 | + | 140 | x | − | 10 | x | x | = | 5280 |