Question

2(n+3)!=(n+4)!
!-factorial
Cat este n?

Answer 1

$2(n+3)!=(n+4)! \ \ \ |:(n+3)! \\\\ \hbox{Impartim relatia cu cel mai mic numar factorial comun} \\\\\\ 2* 1=n+4 \\\\ n=2-4 \\\\ \boxed{n=-2}$