Respuesta :

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]