Answer: 5
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Step-by-step explanation:
Focus on the z terms only. Ignore everything else.
Up top in the numerator we have z^6
In the denominator we have z without an exponent, but it's identical to z^1
We want to divide z^6 over z^1.
Use this rule: (a^b)/(a^c) = a^(b-c)
We subtract the exponents to say (z^6)/(z^1) = z^(6-1) = z^5