The first step for solving this expression is to express it with a positive exponent using [tex] a^{-n} = \frac{1}{ a^{n} } [/tex].
[tex]- \frac{1}{(5y)^{4} } [/tex]
According to the exponent rules,, to raise a product to a power you must raise each factor to that power. This rule will change the expression to the following:
[tex] -\frac{1}{625 y^{4} } [/tex]
This makes the correct answer to your question [tex] -\frac{1}{625 y^{4} } [/tex],, or option D.
Let me know if you have any further questions.
:)
