IMO LONGLISTED PROBLEM 1976

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MATHPRITOM
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IMO LONGLISTED PROBLEM 1976

Unread post by MATHPRITOM » Mon May 02, 2011 12:30 am

For $a,b,c,d\ge0$ ,prove the inequality $a^4+b^4+c^4+d^4+2abcd \ge a^2b^2+a^2c^2+a^2d^2+b^2c^2+b^2d^2+c^2d^2$.

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