1) x^2-2x-3=0
2) x^3+x^2=x+1

1) D=16x1=(2+4)/2=3x2=-12) x^3+x^2-(x+1)=0x^2(x+1)-(x+1)=0(x+1)(x^2-1)=0(x+1)(x-1)(x+1)=0x1=1; x2=-1