Răspunsuri

2014-08-31T17:54:22+03:00
N=2007 + 2*(1+2006)*2006/2

n=2007 + 2007 *2006

n=2007(1+2006)

n=2007*2007

n=2007²  -este pp
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2014-08-31T18:17:44+03:00
1+2+3+....+n=n(n+1):2 ⇒ 1+2+3+...+2006=2006*2007:2=1003*2007
n=2007+2*1003*2007=2007(1+2006)=2007^2
Daca n=x^2= 2007^2 rezulta ca n este patrat perfect

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