Question

puteti sa - mi explicati rezolvarea asta ?
aranjamente de 2012 elemente cate doua din care se scade combinatii de de 2011 elenente cate unul = 2011 la patrat

Answer 1

prin calcl direct aplicand formulele pt aranjamente si pt combinari
nu e nimic de explicat e de calculat
vezi atasament
as simple as that!

Answer 2

A de 2012 luate cate 2 = 2012!/(2012-2)!=2012!/2010!=2011*2012
C de 2011 luate cate 1 = 2011!/[1!*(2011-1)!= 2011!/2010!= 2011

A de 2012 luate cate 2 - C de 2011 luate cate 1= 2011*2012-2011= 2011(2012-1)=2011*2011= 2011^2-= 4044121