Answer
$\frac{-2\sqrt{ab}}{5}$
Work Step by Step
In order to solve this problem, we use the rules of exponents to get the square root of b in the numerator:
$\frac{ -2\sqrt{ab^2}\sqrt{b^{-1}}}{5} \\ \frac{-2\sqrt{ab^{2-1}}}{5}$
$\frac{-2\sqrt{ab}}{5}$
