Sửa đề: \(3x^2+3y^2+4xy+2x-2y+2=0\)
=>\(2x^2+4xy+2y^2+x^2+2x+1+y^2-2y+1=0\)
=>\(2\left(x+y\right)^2+\left(x+1\right)^2+\left(y-1\right)^2=0\)
=>\(\left\{{}\begin{matrix}x+y=0\\x+1=0\\y-1=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=-1\\y=1\end{matrix}\right.\)