2 | × | 3 | × | 4 | × | 5 | × | 6 | × | 7 | ( | n | − | 2 | ) | − | 2 | × | 3 | × | 4 | × | 5 | × | 6 | = | 0 |
方程左边 = | 5040 | ( | n | − | 2 | ) | − | 720 | ( | n | + | 8 | ) |
5040 | ( | n | − | 2 | ) | − | 720 | ( | n | + | 8 | ) | = | 0 |
方程左边 = | 5040 | n | − | 5040 | × | 2 | − | 720 | ( | n | + | 8 | ) |
= | 5040 | n | − | 10080 | − | 720 | ( | n | + | 8 | ) |
= | 5040 | n | − | 10080 | − | 720 | n | − | 720 | × | 8 |
= | 5040 | n | − | 10080 | − | 720 | n | − | 5760 |
= | 4320 | n | − | 15840 |
4320 | n | − | 15840 | = | 0 |
4320 | n | = | 0 | + | 15840 |
4320 | n | = | 15840 |
n | = | 15840 | ÷ | 4320 |
= | 15840 | × | 1 4320 |
= | 11 | × | 1 3 |
n | = | 11 3 |
n | = | 3.666667 |