x-y=-31 ...or y=x+31... & x*y=-140 . . . x*(x+31)=-140 . . . x^2 +31x +140=0 . . . quadratik equashun giv roots=-5.4875078 & -25.5124922 . . . tri x=-25.5124922, then y=x+31=+5.4875078 . . . x*y=(-25.5124922)*(+5.487578)=-139.9999999999 . . . kloes nuf