ĐKXĐ: ...
\(\Leftrightarrow\left\{{}\begin{matrix}2x^2y=y^2+1\\2xy^2=x^2+1\end{matrix}\right.\) \(\Rightarrow\frac{x}{y}=\frac{y^2+1}{x^2+1}\)
\(\Leftrightarrow x^3+x=y^3+y\Leftrightarrow\left(x-y\right)\left(x^2+y^2-xy\right)+\left(x-y\right)=0\)
\(\Leftrightarrow\left(x-y\right)\left(\left(x^2-\frac{y}{2}\right)^2+\frac{3y^2}{4}+1\right)=0\)
\(\Rightarrow x=y\)
\(\Rightarrow2x^3=x^2+1\Leftrightarrow\left(x-1\right)\left(2x^2+x+1\right)=0\)
\(\Rightarrow x=1\Rightarrow y=1\)