3x+y=2 x^2-y^2=-12 y=2-3x x^2-y^2=-12 x^2-(2-3x)^2=-12 y=2-3x1 y=2-3x2 x^2-4+12x-9x^2=-12 y=2-12 y=2+3 -8x^2+12x+8=0 y=-10 y=5 2x^2-3x-2=0 D=9+16 D=25 x1=(3+5)/2=4 x2=(3-5)/2=-1