HPT \(\Rightarrow x^2+2y+1=y^2-2x+1\)
\(\Leftrightarrow\left(x+1\right)^2-\left(y-1^2\right)=0\)
\(\Leftrightarrow\left(x+y\right)\left(x-y+2\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=-y\\x-y=-2\end{matrix}\right.\) \(\Leftrightarrow...\) (Thế x vào phương trình)