Răspunsuri

2014-10-14T21:32:28+03:00

399 = 7·57

n=7+7² +7³+7^4 +.......+7^2009  + 7^2010 =7[(1+7+7²)+7³(1+7+7²)  +.................+7^2008 (1+7+7²)] = 7·57(1+7³ +.........) ⇒n= divizibil cu 399

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