### Home > AC > Chapter 12 > Lesson 12.4.1 > Problem 12-67

12-67.

Evaluate the expression below when and

*.*

Start by simplifying the expression.

Remember that when you multiply numbers with the same base, you can add the exponents together.

Substitute the given values for and

*then simplify.*

Fractional exponents represent a power and a root.

The root is determined by the denominator, and the power by the numerator.

For example, the exponent for