Answer
$-2b^3\sqrt {5a}$
Work Step by Step
$-\sqrt {20ab^6}=-\sqrt {4b^6}\sqrt {5a}=-2b^3\sqrt {5a}$
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.