1,$\left\{\begin{matrix} x^2(y+1)(x+y+1)=3x^2-4x+1 & & \\ xy+x+1=x^2 & & \end{matrix}\right.$
2,$\left\{\begin{matrix} xy^2+4y^2+8=x(x+2) & & \\ x+y+3=3\sqrt{2y-1} & & \end{matrix}\right.$
3,$\left\{\begin{matrix} 2x^2+4y^2+x=19 & & \\ x^2+y^2+y=7 & & \end{matrix}\right.$
4,$\left\{\begin{matrix} \sqrt{3}(x-y)=2\sqrt{xy} & & \\ 2x-y^2=8 & & \end{matrix}\right.$