Question 889116
{{{(n+1)! = 12(n-1)!}}}
{{{(n+1)n(n-1)!=12(n-1)!}}}
{{{n(n+1)=12}}}
{{{n^2+n-12=0}}}
{{{(n+4)(n-3)=0}}}
Only the positive solution works here.
{{{n-3=0}}}
{{{highlight(n=3)}}}