[tex]y=\frac{x+5}{\sqrt{x}+2}<=>x-y\sqrt{x}+5-2y=0[/tex]
pt có nghiệm dương [tex]\left\{\begin{matrix} y>0\\ 5-2y>0\\ \Delta \geq 0 \end{matrix}\right.<=>\left\{\begin{matrix} y>0\\ y<\frac{5}{2}\\ y^2-4(5-2y)\geq 0 \end{matrix}\right.<=>y\geq 2 =>min=2[/tex]