![](https://blog.hocmai.vn/wp-content/uploads/2017/07/hot.gif)
![](https://blog.hocmai.vn/wp-content/uploads/2017/07/hot.gif)
Cho a+b+c=3, a,b,c dương
Chứng minh rằng [tex]\frac{1}{a^{2}+2b^{2}+3}+\frac{1}{b^{2}+2c^{2}+3}+\frac{1}{c^2+2a^{2}+3}\leq \frac{1}{2}[/tex]
Chứng minh rằng [tex]\frac{1}{a^{2}+2b^{2}+3}+\frac{1}{b^{2}+2c^{2}+3}+\frac{1}{c^2+2a^{2}+3}\leq \frac{1}{2}[/tex]