PLEAsE HELP! I have been working on this question for a bout 3 hours. equation is in the middle and answer options are on the side.

[tex] \frac{ {z}^{3} {x}^{6} }{ {z}^{4} {x}^{6} } \\ = {z}^{3 - 4} x ^{6 - 6} \\ = {z}^{ - 1} \\ = \frac{1}{z} [/tex]
Answer:
[tex]c. \: \frac{1}{z} [/tex]
Hope you could understand.
If you have any query, feel free to ask.