Using the equation a-b=2, we can solve that a = 2+b.
We can then <u>substitute that into the expression</u> given to get 3^b/3^(2+b).
Since <u>they have the same base, we can subtract the exponents from the numerator and denominator</u> to get 3^(b-2-b) which <em>simplifies to 3^-2.</em>