Answer:
8m^21/y^3
Explanation:
The relevant rules of exponents are ...
(a^b)/(a^c) = a^(b-c)
(a^b)^c = a^(bc)
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There is nothing here to solve. The expression can be simplified as follows:

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Additional comment
We cannot tell if your variable is v or y. We have assumed y. If it is v, you can make the necessary replacement.