Difference between revisions of "Mock AIME 5 2005-2006 Problems/Problem 5"
(New page: ==Problem== Find the largest prime divisor of <math>25^2+72^2</math>. ==Solution== <math>25^2+72^2=5^4+4\cdot 6^4</math>, and we can use the Sophie Germain Identity on that to get <...) |
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Revision as of 15:58, 13 February 2008
Problem
Find the largest prime divisor of 
.
Solution
, and we can use the Sophie Germain Identity on that to get
![\[25^2+72^2=(5^2+2\cdot 6^2+2\cdot 5\cdot 6)(5^2+2\cdot 6^2-2\cdot 5\cdot 6)=157\cdot 37\]](http://latex.artofproblemsolving.com/d/8/d/d8dbc02ec8c1c15a8a73f65f5ca77aa601fb3d02.png)
.
is the largest prime factor of that.
