x1+x2=-b/a , x1*x2=c/a
1/2-1/3=-b/a , (1/2)*(-1/3)=c/a
a=-6b , a=-6c , b=c
cx²-bx+a=0
cx²-cx-6c=0 , x²-x-6=0 , (x-3)(x+2)=0 , x1=3 ,x2=-2