9514 1404 393
Answer:
D. 81/m^7
Step-by-step explanation:
The applicable rules of exponents are ...
(ab)^c = (a^c)(b^c)
(a^b)^c = a^(bc)
(a^b)(a^c) = a^(b+c)
a^-b = 1/a^b
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Using these, your expression simplifies to ...
[tex](3m^{-4})^3(3m^5)=(3^3)(3)(m^{-4\cdot3+5})=81m^{-7}=\boxed{\dfrac{81}{m^7}}[/tex]
