\(P=2\left(x^2+2xy+y^2\right)+4\left(x+y\right)+3y^2-6y+2028\)
\(=2\left(x+y\right)^2+4\left(x+y\right)+2+3\left(y^2-2y+1\right)+2023\)
\(=2\left(x+y+1\right)^2+3\left(y-1\right)^2+2023\ge2023\)
\(P_{min}=2023\) khi \(\left\{{}\begin{matrix}x+y+1=0\\y-1=0\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}x=-2\\y=1\end{matrix}\right.\)