Question

Ajutați-mă va roog. Dau coroana!​

Answer 1

$\it 1)\ \dfrac{(n+2)!}{(n+1)!}= 19 \Rightarrow \dfrac{(n+1)!(n+2)}{(n+1)!}=19 \Rightarrow n+2=9|_{-2} \Rightarrow n=7\\ \\ \\ 2)\ \dfrac{(n+1)!}{n-1}=12 \Rightarrow \dfrac{(n-1)!n(n+1)}{(n-1)!}=12 \Rightarrow n(n+1)=12=3\cdot4\Rightarrow n=3$