$a,b,c$ are real positive numbers ,what is the proof that :
$$\frac{2a}{3a^2+b^2+2ac} +\frac{2b}{3b^2+c^2+2ab}+\frac{2c}{3c^2+a^2+2bc}\le\frac{3}{a+b+c}$$
$a,b,c$ are real positive numbers ,what is the proof that :
$$\frac{2a}{3a^2+b^2+2ac} +\frac{2b}{3b^2+c^2+2ab}+\frac{2c}{3c^2+a^2+2bc}\le\frac{3}{a+b+c}$$