Question

Решить систему уравнений: первое: x+y-xy=-14; второе: x+y+xy=2

Answer 1

см. файл
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\

Answer 2

$\left \{ {{x+y-xy=-14} \atop {x+y+xy=2}} \right. \left \{ {{2x+2y=-12} \atop {x+y+xy=2}} \right. \left \{ {{2(x+y)=-12} \atop {x+y+xy=2}} \right. \left \{ {{x+y=-6} \atop {-6+xy=2}} \right. \left \{ {{x+y=-6} \atop {xy=8}} \right.$

$\left \{ {{x=-2} \atop {y=-4}} \right.$  или  $\left \{ {{x=-4} \atop {y=-2}} \right.$