Question

Решите систему уравнений, пользуясь теоремой, обратной теореме Виета​

Answer 1

$1)\left \{ {{x+y=-10} \atop {xy=21}} \right. \\\\\\\left[\begin{array}{ccc}\left \{ {{y=-3} \atop {x=-7}} \right. \\\left \{ {{y=-7} \atop {x=-3}} \right. \end{array}\right\\\\Otvet:\boxed{(-3;-7),(-7;-3)}$

$2)\left \{ {{xy=-30} \atop {x+y=1}} \right. \\\\\left[\begin{array}{ccc}\left \{ {{y=6} \atop {x=-5}} \right. \\\left \{ {{y=-5} \atop {x=6}} \right. \end{array}\right\\\\Otvet:\boxed{(-5;6),(6;-5)}$

$3)\left \{ {{x+y=-6} \atop {xy=-16}} \right.\\\\\left[\begin{array}{ccc}\left \{ {{y=2} \atop {x=-8}} \right. \\\left \{ {{y=-8} \atop {x=2}} \right. \end{array}\right\\\\Otvet:\boxed{(-8;2),(2;-8)}$

$4)\left \{ {{x+y=9} \atop {xy=-10}} \right.\\\\\left[\begin{array}{ccc}\left \{ {{y=10} \atop {x=-1}} \right. \\\left \{ {{y=-1} \atop {x=10}} \right. \end{array}\right\\\\Otvet:\boxed{(10;-1),(-1;10)}$