bantun dong tolong:(:(

[tex] \frac{n!}{(n - 2)!} = \frac{n.(n - 1)(n - 2)!}{(n - 2)!} = n(n - 1) = n^{2} - n [/tex]

[tex] \frac{(n - 4)!}{n!} = \frac{(n - 4)!}{n.(n - 1)(n - 2)(n - 3)(n - 4)!} = \frac{1}{n(n - 1)(n - 2)(n - 3)} [/tex]

[tex] \frac{(n - 3)!}{(n + 1)!} = \frac{(n - 3)!}{(n + 1).n.(n - 1)(n - 2)(n - 3)!} = \frac{1}{(n + 1)n(n - 1)(n - 2)} [/tex]