Помогите решить систему уравнений 3(x-y)=x+y x^2-y^2=3

[[latex] \left \{ {{3x-3y=x+y} \atop { x^{2}-y^{2} =3}} \right. \left \{ {{2x=4y} \atop {x^{2}-y^{2} =3}} \right. \left \{ {{x=2y} \atop {4 y^{2}-y^{2}=3 }} \right. \left \{ {{x=2y} \atop { y^{2} =1}} \right. \left \{ {{y_{1}=1};{y_{2}=-1} \atop {x_{2}=2};{x_{2}=-2}} \right. [/latex]