Intermediate Algebra (6th Edition)

Published by Pearson
ISBN 10: 0321785045
ISBN 13: 978-0-32178-504-6

Chapter 7 - Section 7.6 - Radical Equations and Problem Solving - Exercise Set - Page 453: 43

Answer

$x = \{ 1, \frac{1}{4}\}$

Work Step by Step

$\sqrt (5x-1) -\sqrt x + 2 = 3 $ To separate the radicals add $-2$ both sides. $\sqrt (5x-1) -\sqrt x +2 - 2 = 3 - 2 $ $\sqrt (5x-1) -\sqrt x = 1 $ Squaring on both sides. $(\sqrt (5x-1) -\sqrt x)^{2} = 1^{2} $ $(5x-1) + x - 2 \sqrt (5x-1)\sqrt x = 1$ $6x-1 - 2 \sqrt (5x-1)\sqrt x = 1$ $6x-1 -1 = 2 \sqrt (5x-1)\sqrt x $ $6x-2 = 2 \sqrt (5x-1)\sqrt x $ $2(3x-1) = 2 \sqrt (5x-1)\sqrt x $ Dividing both sides by $2$ $(3x-1) = \sqrt (5x-1)\sqrt x $ Squaring on both sides. $(3x-1)^{2} = (\sqrt (5x-1)\sqrt x )^{2}$ $9x^{2}-6x+1 = x(5x-1)$ $9x^{2}-6x+1 = 5x^{2}-x$ $9x^{2}-6x+1 - 5x^{2}+x = 0$ $4x^{2}-5x+1 = 0$ By factoring, $(4x-1)(x-1)=0$ $x = 1$ or $x= \frac{1}{4}$ $x = \{ 1, \frac{1}{4}\}$ Substituting $x$ values in the given equation, $x= 1$ satisfies the equation. So, $1$ is the only solution.
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.