(n+2)!/n!=72 tentukan nilai n ?

[tex] \frac{(n + 2) (n + 1)(n)}{(n)} \\ {n }^{2} + 3n + 2 = 72 \\ {n}^{2} + 3n - 70 = 0 \\ (n - 7)(n + 10) \\ \: n = 7 \: \: \: \: n = - 10 \\ [/tex]
jawaban nya n = 7