9514 1404 393
Answer:
81m^4·n^4
Step-by-step explanation:
"Simplify" in this context means "remove parentheses." The applicable rule of exponents is ...
(ab)^c = (a^c)(b^c)
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[tex](3mn)^4=3^4m^4n^4=\boxed{81m^4n^4}[/tex]