Question

como resolvover (n+2)!.(n-2)!/(n+1)!.(n-1)!=4

Answer 1

$\frac{(n+2)!(n-2)!}{(n+1)!(n-1)!} =4=\ \textgreater \ \frac{(n+2)(n+1)!(n-2)!}{(n+1)!(n-1)(n-2)!} =4 \\ \frac{n+2}{n-1} =4=\ \textgreater \ 4n-4=n+2=\ \textgreater \ 4n-n=2+4=\ \textgreater \ 3n=6=\ \textgreater \ n=2$