\(2x^2+y^2+2xy-2x+2=0\)
\(\Leftrightarrow\left(x^2+2xy+y^2\right)+\left(x^2-2x+1\right)+1=0\)
\(\Leftrightarrow\left(x+y\right)^2+\left(x-1\right)^2=-1\) ( vô lý )
( vì \(\left(x+y\right)^2\ge0\forall x,y;\left(x-1\right)^2\ge0\forall x\) )
Vậy ko có g/t \(x;y\) thỏa mãn