| ( | 20 | ( | 60 | − | X | ) | + | 300 | ) | ( | X | − | 40 | ) | = | 6080 |
| Left side of the equation = | 20 | ( | 60 | − | X | ) | ( | X | − | 40 | ) | + | 300 | ( | X | − | 40 | ) |
| = | 20 | × | 60 | ( | X | − | 40 | ) | − | 20 | X | ( | X | − | 40 | ) | + | 300 | ( | X | − | 40 | ) |
| = | 1200 | ( | X | − | 40 | ) | − | 20 | X | ( | X | − | 40 | ) | + | 300 | ( | X | − | 40 | ) |
| = | 1200 | X | − | 1200 | × | 40 | − | 20 | X | ( | X | − | 40 | ) | + | 300 | ( | X | − | 40 | ) |
| = | 1200 | X | − | 48000 | − | 20 | X | ( | X | − | 40 | ) | + | 300 | ( | X | − | 40 | ) |
| = | 1200 | X | − | 48000 | − | 20 | X | X | + | 20 | X | × | 40 | + | 300 | ( | X | − | 40 | ) |
| = | 1200 | X | − | 48000 | − | 20 | X | X | + | 800 | X | + | 300 | ( | X | − | 40 | ) |
| = | 2000 | X | − | 48000 | − | 20 | X | X | + | 300 | ( | X | − | 40 | ) |
| = | 2000 | X | − | 48000 | − | 20 | X | X | + | 300 | X | − | 300 | × | 40 |
| = | 2000 | X | − | 48000 | − | 20 | X | X | + | 300 | X | − | 12000 |
| = | 2300 | X | − | 60000 | − | 20 | X | X |
| 2300 | X | − | 60000 | − | 20 | X | X | = | 6080 |