P
pl09


Cho $a,b,c >0$ . Chứng minh rằng:
$\dfrac{1}{a}+\dfrac{1}{b}+\dfrac{1}{c} \ge \dfrac{a^{2}+2b^{2}}{a^{3}+2b^{3}}+\dfrac{b^{2}+2c^{2}}{b^{3}+2c^{3}}+\dfrac{c^{2}+2a^{2}}{c^{3}+2a^{3}}$
$\dfrac{1}{a}+\dfrac{1}{b}+\dfrac{1}{c} \ge \dfrac{a^{2}+2b^{2}}{a^{3}+2b^{3}}+\dfrac{b^{2}+2c^{2}}{b^{3}+2c^{3}}+\dfrac{c^{2}+2a^{2}}{c^{3}+2a^{3}}$
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