simplify them. 3. Use the definition of the rational exponents to write expressions with radicals. Then, a) 491/2 b) 641/3 c) -1251/3Part B. Apply the Concepts Assume all variables represent positive real numbers. 1. Evaluate each of the following roots without using a calculator. a) 81 b) V - -81 c) -V815. Use the properties of exponents to simplify each of the following as much as possible. a) x3/7 . x2/7 b) y1/6 . y-7/6 c) (a3/2) 4/3