Đk: x>/ 0
\(5x-2\sqrt{x}\left(y+2\right)+y^2+1=0\)
\(\Leftrightarrow\left(x+2\sqrt{x}\cdot y+y^2\right)+\left(4x+4\sqrt{x}+1\right)=0\)
\(\Leftrightarrow\left(\sqrt{x}+y\right)^2+\left(2\sqrt{x}+1\right)^2=0\)
\(\Leftrightarrow\left\{{}\begin{matrix}\sqrt{x}+y=0\\2\sqrt{x}+1=0\end{matrix}\right.\left(VN\right)\)