Thanks for clarifying your meaning.
(6x^5 z)^3 divided by 4x^4 z^2 is equivalent to:
(6x^5 z)^3
---------------
4x^4 z^2
One of the easist approaches to simplifying this is treating the coefficients, the x powers and the z powers separately:
(6/4) * (x) * (z^3 / z^2)
This results in (3/2)*x*z (answer)
