Answer:
maybe 4
Step-by-step explanation:
The fraction reduces to ...
[tex]\dfrac{5^6}{5^2}=5^{6-2}=5^4[/tex]
This could mean that a=5, b=4.
The value can be rewritten using other values for a, for example, ...
5^4 = 25^2 = 125^(4/3) = 625^1
The value of b depends on the value of a, which is not specified.