Not sure how to phrase it, but basically, Rational exponents are just roots in exponent form. Ex: 3rd root of x = x^(1/3).
This means you can swtich back and forth with them easily to simplify problems. This also means that properties of both can be applied to both (although they have identical properties)
So if you have a^(1/m) * a^(1/n) then because of exponents properties you know we can simplify with a^(1/m + 1/n) This is the same with negative exponents and other properties.
Sorry if my explanation is bad, and hopefully you learn, even if a little.