由韦达定理x1+x2=-(-3)/1=3x1*x2=(-1)/1=-1所以x1x2^2+x1^2x2=x1x2(x1+x2)=(-1)*3=-3
x1+x2=3,x1*x2=-1x1x2^2+x1^2x2=x1x2(x2+x1)=-1*3=-3
