Câu hỏi 99
Chứng minh với $x,y,z\gt 0$, $xyz=1$,
$$\frac1{x+y^{20}+z^{11}}+\frac1{y+z^{20}+x^{11}}+\frac1{z+x^{20}+y^{11}}\le1.$$
$$\frac1{x+y^{20}+z^{11}}+\frac1{y+z^{20}+x^{11}}+\frac1{z+x^{20}+y^{11}}\le1.$$
MathNet 2011 Câu hỏi 99
Math Olympiad Vault · MathNet 2011