| ( | 20 | + | 5 | x | ) | ( | 44 | − | x | ) | = | 1600 |
| Left side of the equation = | 20 | ( | 44 | − | x | ) | + | 5 | x | ( | 44 | − | x | ) |
| = | 20 | × | 44 | − | 20 | x | + | 5 | x | ( | 44 | − | x | ) |
| = | 880 | − | 20 | x | + | 5 | x | ( | 44 | − | x | ) |
| = | 880 | − | 20 | x | + | 5 | x | × | 44 | − | 5 | x | x |
| = | 880 | − | 20 | x | + | 220 | x | − | 5 | x | x |
| = | 880 | + | 200 | x | − | 5 | x | x |
| 880 | + | 200 | x | − | 5 | x | x | = | 1600 |