So i was following the textbook with dividing the polynomial to find a quadratic factor..

the polynomial is 4x^3 -10x^2 -8x +6 =0

and i was dividing it by x-3 as it is a root of it.

I divided it and got the answer (x-3)(2x^2-4x-20)-54

What else do i need to do to it, to find the quadratic factor.. or to set it out right?

Need help!!!