Intermediate Algebra: Connecting Concepts through Application

Published by Brooks Cole
ISBN 10: 0-53449-636-9
ISBN 13: 978-0-53449-636-4

Chapter 8 - Radical Functions - 8.4 Solving Radical Equations - 8.4 Exercises - Page 654: 66

Answer

$x= -1555 $

Work Step by Step

Given \begin{equation} \sqrt[5]{2 x-15}+9=4. \end{equation} Start by rewriting the radical as a power of fraction and then solve for $x$. \begin{equation} \begin{aligned} \sqrt[5]{2 x-15}+9&=4\\ \left(5 x+2\right)^{\frac{1}{5}}&= 4\\ \left(\left(2 x-15\right)^{\frac{1}{5}}\right)^3& = \left( -5\right)^5 \\ 2 x-15& =-3125\\ x&= \frac{-3125+15}{2}\\ & = -1555. \end{aligned} \end{equation} Check. \begin{equation} \begin{aligned} \left(2 \cdot(-1555)-15\right)^{\frac{1}{5}}+9&\stackrel{?}{=}4\\ 4& =4\quad \checkmark. \end{aligned} \end{equation} The solution is $x= -1555 $.
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.