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thaopro1230


Cho a, b, c là độ dài 3 cạnh tam giác.
C/m [TEX]\frac{1}{a+b-c}+\frac{1}{b+c-a}+\frac{1}{c+a-b}\geq\frac{1}{a}+\frac{1}{b}+\frac{1}{c}[/TEX]
C/m [TEX]\frac{1}{a+b-c}+\frac{1}{b+c-a}+\frac{1}{c+a-b}\geq\frac{1}{a}+\frac{1}{b}+\frac{1}{c}[/TEX]