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Cho x+y+z =1 ; x,y,z> 0 .CM
[TEX]\frac{3}{xy+yz+zx}+\frac{2}{x^2+y^2+z^2} > 14[/TEX]
[TEX]\frac{3}{xy+yz+zx}+\frac{2}{x^2+y^2+z^2} > 14[/TEX]
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