Please help simplify with steps 

Remember that you can always multiply or divide BOTH the numerator and denominator
of the fraction by anything you want to.  You just have to do exactly the same to both of
them.

The way to simplify a fraction is to divide both the numerator and denominator by their
greatest common factor.

Do you see all of those 'x's on the top and bottom ?  The top and bottom can
both be divided by x-cubed.

Numerator:
Divide (-4³) by x³, and you have (-4) left.

Denominator:
Divide (x³ - 2x⁴) by x³, and you have (1 - 2x) left.

So, the simplified fraction is [  -4 / (1 - 2x)  ].

That's a perfectly good answer, but you could make it look a little prettier
if you multiply the top and bottom both by -1 .  Then it would be

                             4 / (2x - 1) .

Either one is fine.