How to express as a quotient of base n integers

[Meager]

Can someone guide me on how to express

(.a1a2a3a4a5) base n as a quotient of base n integers.

There is a bar over a3a4a5.

 

[dodo]

Well, I would decompose your number as: .a1a2 + n^-2 * .a3a4a5 (bar).

The first term should be easy; for the last part after the power of n (call it X), note that X*n^3 - X = a3a4a5, and solve for X. Then you should be able to combine the parts into a single fraction.