Question

5^x= 1/625

Answer 1

\[\frac{1}{625} = 5^{-4}\] therefore \[\large 5^x = \frac{1}{625} \implies 5^x = 5^{-4} \implies x = -4\]

Answer 2

Yes. Once you get the same base, you can just ignore them and solve what's in the exponents.