Решение систем уравнений второй степени

Решите задачу:

$\left \{ {{x-3y+6=0} \atop {y^2-xy=-8}} \right. \\ \left \{ {{x=3y-6} \atop {y^2-y(3y-6)=-8}} \right. \\ \left \{ {{x=3y-6} \atop {y^2-3y^2+6y+8=0}} \right. \\ \left \{ {{x=3y-6} \atop {2y^2-6y-8=0}} \right. \\ \left \{ {{x=3y-6} \atop {y^2-3y-4=0}} \right. \\ \left \{ {{y_1=4} \atop {y_2=-1}} { {{x_1=6} \atop {x_2=-9}} \right. \\ OTBET: (6;4); (-9;-1)$