-3x^2-14x-7=(x-1)^2 -3x^2-14x-7=x^2-2x+1 -3x^2-14x-7-x^2+2x-1=0 -4x^2-12x-8=0 4x^2+12x+8=0 x^2+3x+2=0 D=9-4*1*2=9-8=1 x1=-3+1\2=-1 x2=-3-1\2=-4\2=-2