1) x1=3; x2=-1/3
По т.Виета
x1+x2=3-1/3=2 2/3=8/3=-p;
x1*x2=3*(-1/3)=-1=q;
x²-8/3*x-1=0; |*3
3x²-8x-3=0;
D=64+36=100;
x1=(8+10)/6=18/6=3;
x2=(8-10)/6=-2/6=-1/3.
2) x1=-2; x2=-1/2;
x1+x2=-2-1/2=-5/2=-p;
x1*x2=-2*(-1/2)=1=q;
x²+5/2*x+1=0; |*2
2x²+5x+2=0;
D=25-16=9;
x1=(-5-3)/4=-8/4=-2;
x2=(-5+3)/4=-2/4=-1/2;