Помогите решить систему уравнений,пожалуйста x-y+xy=-11, x-y-xy=1.

Решите задачу:

$+ \left \{ {{x-y+xy=-11} \atop {x-y-xy=1}} \right. \\ -------- \\ 2x-2y=-10 \\ x-y=-5 \\ x=y-5 \\ \left \{ {{x=y-5} \atop {y-5-y-(y-5)y=1}} \right. =\ \textgreater \ \left \{ {{x=y-5} \atop {-5-y^2+5y=1}} \right. =\ \textgreater \ \left \{ {{x=y-5} \atop {-y^2+5y-6=0}} \right. =\ \textgreater \ \\ \left \{ {{x=y-5} \atop {-(y-2)(y-3)=0}} \right. =\ \textgreater \ \left \{ {{x_1=-3;x_2=-2} \atop {y_1=2;y_2=3}} \right.$