Which is the simplified form of (9c^-9)^-3 1. 9c^27 2. 1/729^c27 3. 729^27 4. 9/c^27

It may be easier if you rewrite the given expression (9c^-9)^-3 as:

        9                                                     c^9               c^27
[ ]^(-3), which comes out to [ ]^3 =
      c^9                                                     9                   9^3

In problems such as this one, try to get rid of all negative exponents.