9514 1404 393
Answer:
A) x^-28*7^-56
Step-by-step explanation:
The applicable rules of exponents are ...
(a^b)^c = a^(bc)
(ab)^c = (a^c)(b^c)
1/a^b = a^-b
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[tex]\left(\dfrac{x^4}{7^{-8}}\right)^{-7}=(x^47^8)^{-7}=x^{4(-7)}7^{8(-7)}=\boxed{x^{-28}7^{-56}}[/tex]