x1*x2=-1/2,x1+x2=-3/2;
(1)=x1*x2-(x1+x2)+1=2;
(2)=x1*x2(x1^2+x2^2)=x1*x2[(x1^2+x2^2+2x1*x2)-2x1*x2]=x1*x2[(x1+x2)^2-2x1*x2]=-13/8