Question

Каковы корни уравнения,если:
x+y=-5
xy=12

Answer 1

$left { {{x+y=-5} atop {xy=12}} right. \ \ left { {{x=-5-y} atop {y(-5-y)=12}} right. \ \ left { {{x=-5-y} atop {-5y-y^{2}=12}} right. left { {{x=-5-y} atop {y^{2}+5y+12=0}} right. \ \ y^{2}+5y+12=0 \ D=25-4*12=-13<0$

Корней нет.