Răspunsuri

2014-11-10T15:32:02+02:00
 2+4+6+.....+1002(1+2+3+...+50)=
1+2+3+..+50 = 50*51/2
deci 
2*50*51/2  simplificam 2 cu 2 si ramane
50*51=> nu e patrat perfect