Chapter 11 - Additional Topics - 11.3 - Fractional Exponents - Problem Set 11.3 - Page 489: 18

-3

First of all, remember that raising a number to the ⅓ power is the same as taking the cube root of that number. Also, recall, when a number is raised to the third power, the cube root cancels out the exponent. Thus, we obtain: $\sqrt[3] {-27}=\sqrt[3] {(-3)^{3}}=-3$