Answer:
[tex]\frac{1}{5^{4}}[/tex] = [tex]\frac{1}{625}[/tex] = 0.0016
Step-by-step explanation:
I'm assuming you mean [tex]5^{-4}[/tex] (which could also be written as 5^-4, for future reference).
Negative exponents actually mean you'd use the term in the denominator, taking away the negative portion. It's difficult to explain in words, and is easier to see.
[tex]5^{-4}[/tex] = [tex]\frac{1}{5^{4}}[/tex]
Notice how the -4 changes to 4, and it becomes the denominator.
[tex]5^{4}[/tex] is also 625, so [tex]5^{-4}[/tex] is also 1/625, or the decimal version (0.0016).
I hope this helps!