giải hpt: a) \(\left\{{}\begin{matrix}x^2+y^2+1=2\left(xy-x+y\right)\\x^3+3y^2+5x-12=\left(12-y\right)\sqrt{3-x}\end{matrix}\right.\)
b) \(\left\{{}\begin{matrix}x+\sqrt{x^2+2x+2}=\sqrt{y^2+1}-y-1\\x^3-\left(3x^2+2y^2-6\right)\sqrt{2x^2-y^2-2}=0\end{matrix}\right.\)