y²+7y+10=0;
D=49-40=3²;
y₁=(-7-3)/2=-5;
y₂=(-7+3)/2=-2;
x₁=7+y₁=7-5=2;
x₂=7+y₂=7-2=5;
ответ:(2;-5)U(5;-2).
{х-у=7; {x=7+у; {x=7+y;
{ху=-10; {у(7+у)=-10; {y²+7y+10=0;
y²+7y+10=0;
D=49-40=3²;
y₁=(-7-3)/2=-5;
y₂=(-7+3)/2=-2;
x₁=7+y₁=7-5=2;
x₂=7+y₂=7-2=5;
ответ:(2;-5)U(5;-2).