[n!/(n-5)!-n!/(n-3)!] / n!/(4! x (n-4)!) si dupa simplificare cu n!= [1/(n-5)!-1/(n-3)!]/1/4!(n-4)!=4!(n-4)! / [(n-4)(n-5)-1]/(n-3)! = 4!(n-3)/ [(n-4)(n-5)-1] =4(n-3)/(n^2-9n+19)
Ajutatima va rog sa o continui dau coroana + 50 de puncte