Respuesta :

9514 1404 393

Answer:

  (d)  b/a

Step-by-step explanation:

The applicable rule of exponents is ...

  (a^b)/(a^c) = a^(b-c)

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Then the expression simplifies to ...

  b^-2/(ab^-3) = b^(-2-(-3))/a = b^1/a = b/a