Step-by-step explanation: If you multiply b*b*b you get b^3. Since b^3 is the denominator and the numerator is 1, you can just multiply the top and bottom by b^-3 to get rid of the denominator. b^3*b^-3 is 1, which effectively removes the denominator, and 1*b^-3 is b^-3. Thus, the answer is b^-3.