[tex]P=\sqrt{\frac{x^{2}}{y^{2}}+\frac{y^{2}}{x^{2}}+2} + \frac{\sqrt{xy}}{x+y}=\sqrt{(\frac{x}{y}+\frac{y}{x})^2} + \frac{1}{\frac{x+y}{\sqrt{xy}}}=\frac{x}{y}+\frac{y}{x}+\frac{1}{\frac{\sqrt{x}}{\sqrt{y}}+\frac{\sqrt{y}}{\sqrt{x}}}=(\frac{\sqrt{x}}{\sqrt{y}}+\frac{\sqrt{y}}{\sqrt{x}})^2+\frac{1}{\frac{\sqrt{x}}{\sqrt{y}}+\frac{\sqrt{y}}{\sqrt{x}}} -2\\\frac{\sqrt{x}}{\sqrt{y}}+\frac{\sqrt{y}}{\sqrt{x}}=t\geq 2\\\rightarrow t^2+\frac{1}{t}-2=\frac{7}{8}t^2+\frac{1}{8}t^2+\frac{1}{t}-2\geq \frac{7}{8}t^2+2.\sqrt{\frac{t}{8}}-2\geq \frac{7}{8}.2^2+2.\sqrt{\frac{2}{8}}-2=\frac{7}{2}+1-2=\frac{5}{2}\\"="\Leftrightarrow x=y[/tex]