Question

Найти x и y, если x+y=6, xy=-3.

Answer 1

x=6-y

(6-y)y=-3
6y-y²+3=0
y²-6y-3=0
D=36-4*(-3)*1=36+12=48
x1=6+√48/2 =6+4√3/2= 3+2√3
x2=3-2√3
y1=6-3-2√3=3-2√3
y2=6-3+2√3=3+2√3