| ( | x | − | 16 | ) | ( | 960 | − | 30 | x | ) | = | 1920 |
| Left side of the equation = | x | ( | 960 | − | 30 | x | ) | − | 16 | ( | 960 | − | 30 | x | ) |
| = | x | × | 960 | − | x | × | 30 | x | − | 16 | ( | 960 | − | 30 | x | ) |
| = | 960 | x | − | x | × | 30 | x | − | 16 | × | 960 | + | 16 | × | 30 | x |
| = | 960 | x | − | x | × | 30 | x | − | 15360 | + | 480 | x |
| = | 1440 | x | − | x | × | 30 | x | − | 15360 |
| 1440 | x | − | x | × | 30 | x | − | 15360 | = | 1920 |