Kinda lost with this one

Question

Given that
hx^3 - 12x^2 - x + 3=(2x-1) (2x+1) (x-k)

find the values of the constants k and h

don't even know where to start

start by expanding the right side.

then you have

hx^3 - 12x^2 - x + 3 = 4x^3 - 4kx^2 - x + k

By comparing "like" terms, h would be 4 and k would be 3