Thinking Mathematically (6th Edition)

Published by Pearson
ISBN 10: 0321867327
ISBN 13: 978-0-32186-732-2

Chapter 5 - Number Theory and the Real Number System - 5.4 The Irrational Numbers - Exercise Set 5.4 - Page 296: 67

Answer

$20\sqrt2-5\sqrt3$

Work Step by Step

Factor each radicand so that one of the factors is a perfect square to obtain: \begin{align*} &=3\sqrt{4(2)}-\sqrt{16(2)}+3\sqrt{36(2)}-\sqrt{25(3)}\\ \end{align*} Simplifiy each radical by taking out the square root of each perfect square factor inside the radical sign to obtain: \begin{align*} &=3(2)\sqrt2-4\sqrt2+3(6)\sqrt2-5\sqrt3\\ &=6\sqrt2-4\sqrt2+18\sqrt2-5\sqrt3\\ &=(6-4+18)\sqrt2-5\sqrt3\\ &=20\sqrt2-5\sqrt3 \end{align*}
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After 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.