Question

Determine o conjunto soluções da equação: (n+2)! . (n-1)! /(n+1)!.(n-1)!=4

Answer 1

$\dfrac{(n+2)!\cdot(n-1)!}{(n+1)!\cdot(n-1)!}=4$

$\dfrac{(n+2)!}{(n+1)!}=4$

$\dfrac{(n+2)(n+1)!}{(n+1)!}=4$

$n+2=4$

$n=2$