Xy=a
a²+a-2=0
a1+a2=-1 U a1*a2=-2
a1=-2 U a2=1
1)xy=-2
2x+y=3⇒y=3-2x
3x-2x²+2=0
2x²-3x-2=0
D=9+16=25
x1=(3-5)/4=-0,5⇒y1=3+1=4
x2=(3+5)/4=2⇒y2=3-4=-1
2)xy=1
2x+y=3⇒y=3-2x
3x-2x²-1=0
2x²-3x+1=0
D=9-8=1
x3=(3-1)/4=0,5⇒y3=3-1=2
x4=(3+1)/4=1⇒y4=3-2=1
(-0,5;4);(2;-1);(0,5;2);(1;1)