Răspuns :
2014+2x(1+2+.....+2013)
2014+2*2013*2014/2 =
2014+2013*2014=
2014(1+2013)=
2014*2014 -> patrat perfect
2014+2*2013*2014/2 =
2014+2013*2014=
2014(1+2013)=
2014*2014 -> patrat perfect
2014+2x2013x2014/2=
2014+213x2014=2014(1+2013)=2014x2014=2014²
deci este patrat perfect
2014+213x2014=2014(1+2013)=2014x2014=2014²
deci este patrat perfect