| 16000 | = | ( | - | 20 | x | + | 2400 | ) | ( | x | − | 60 | ) |
| Right side of the equation = | - | 20 | x | ( | x | − | 60 | ) | + | 2400 | ( | x | − | 60 | ) |
| = | - | 20 | x | x | + | 20 | x | × | 60 | + | 2400 | ( | x | − | 60 | ) |
| = | - | 20 | x | x | + | 1200 | x | + | 2400 | ( | x | − | 60 | ) |
| = | - | 20 | x | x | + | 1200 | x | + | 2400 | x | − | 2400 | × | 60 |
| = | - | 20 | x | x | + | 1200 | x | + | 2400 | x | − | 144000 |
| = | - | 20 | x | x | + | 3600 | x | − | 144000 |
| 16000 | = | - | 20 | x | x | + | 3600 | x | − | 144000 |