The next problem is already a fraction. The top and bottom both contain negative exponents. Since d^{-3} on the bottom has a negative exponent, it is moved to the top of the fraction (numerator). Since the c^{-3} on the top of the fraction has a negative exponent, it is moved to the bottom of the fraction (denominator).

The problem and work is shown below.

The next page shows a variation of this problem.