what do i do if the 5 and 10 are not the same?

\(\dfrac{5^3}{10^{-2}} = \\ \dfrac{5^3}{(2\cdot 5)^{-2}} = \\ \dfrac{5^3}{2^{-2}5^{-2}} = \\ \dfrac{5^{3-(-2)}}{2^{-2}}=\\ \dfrac{5^5}{2^{-2}} =\\ 5^5 2^2 = \\ 12500\)

Another method:

5^3 / 10^-2 = 5^3  *  10^2 = 125 x 100 = 12500