X1*x2=-6 x1+x2=4,5 a) x1x2(x2+x2)=-6(4,5)=-27 b) (x2^2+x1^2)/x1x2=((x1+x2)^2-2x1x2)/x1x2=(4,5^2+12)/-6=-5,375 c) x1^3+x2^2=(x1+x2)(x1^2+x2^2-x1x2)=4,5(4,5^2+18)=172,125