Intermediate Algebra (6th Edition)

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

Chapter 8 - Section 8.1 - Solving Quadratic Equations by Completing the Square - Exercise Set - Page 485: 47

Answer

$y=\dfrac{3}{2}\pm\dfrac{\sqrt{11}}{2}$

Work Step by Step

Using the completing the square method, then, \begin{array}{l} 4y^2-2=12y\\ 4y^2-12y-2=0\\ y^2-3y-\dfrac{1}{2}=0\\ y^2-3y=\dfrac{1}{2}\\ y^2-3y+\left( \dfrac{-3}{2} \right)^2=\dfrac{1}{2}+\left( \dfrac{-3}{2}\right)^2\\ y^2-3y+\dfrac{9}{4}=\dfrac{1}{2}+\dfrac{9}{4}\\ \left( y-\dfrac{3}{2} \right)^2=\dfrac{11}{4}\\ y-\dfrac{3}{2}=\pm\sqrt{\dfrac{11}{4}}\\ y=\dfrac{3}{2}\pm\dfrac{\sqrt{11}}{2} .\end{array}
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.