| 2 | × | 3 | × | 4 | × | 5 | × | 6 | ( | n | − | 2 | ) | − | 2 | × | 3 | × | 4 | × | 5 | ( | n | + | 7 | ) | = | 0 |
| Left side of the equation = | 720 | ( | n | − | 2 | ) | − | 120 | ( | n | + | 7 | ) |
| 720 | ( | n | − | 2 | ) | − | 120 | ( | n | + | 7 | ) | = | 0 |
| Left side of the equation = | 720 | n | − | 720 | × | 2 | − | 120 | ( | n | + | 7 | ) |
| = | 720 | n | − | 1440 | − | 120 | ( | n | + | 7 | ) |
| = | 720 | n | − | 1440 | − | 120 | n | − | 120 | × | 7 |
| = | 720 | n | − | 1440 | − | 120 | n | − | 840 |
| = | 600 | n | − | 2280 |
| 600 | n | − | 2280 | = | 0 |
| 600 | n | = | 0 | + | 2280 |
| 600 | n | = | 2280 |
| n | = | 2280 | ÷ | 600 |
| = | 2280 | × | 1 600 |
| = | 19 | × | 1 5 |
| n | = | 19 5 |
| n | = | 3.8 |