| 2 | × | 3 | × | 4 | ( | n | − | 2 | ) | − | 2 | × | 3 | ( | n | + | 4 | ) | = | 0 |
| 方程左边 = | 24 | ( | n | − | 2 | ) | − | 6 | ( | n | + | 4 | ) |
| 24 | ( | n | − | 2 | ) | − | 6 | ( | n | + | 4 | ) | = | 0 |
| 方程左边 = | 24 | n | − | 24 | × | 2 | − | 6 | ( | n | + | 4 | ) |
| = | 24 | n | − | 48 | − | 6 | ( | n | + | 4 | ) |
| = | 24 | n | − | 48 | − | 6 | n | − | 6 | × | 4 |
| = | 24 | n | − | 48 | − | 6 | n | − | 24 |
| = | 18 | n | − | 72 |
| 18 | n | − | 72 | = | 0 |
| 18 | n | = | 0 | + | 72 |
| 18 | n | = | 72 |
| n | = | 72 | ÷ | 18 |
| = | 72 | × | 1 18 |
| = | 4 | × | 1 |
| n | = | 4 |