Intermediate Algebra for College Students (7th Edition)

Published by Pearson
ISBN 10: 0-13417-894-7
ISBN 13: 978-0-13417-894-3

Chapter 8 - Review Exercises - Page 657: 6

Answer

Given: $x^2+20x$ The coefficient of the $x$-term is $20$. Half of $20$ is $10$, and $(10)^2 = 100$ Thus, add $100$ to both sides to complete the square. $x^2+20x+100=100$ Since, $a^2+2ab+b^2=(a+b)^2$, the equation becomes $(x+10)^2=100$ Apply the square root property to get the value of $x$. $x+10=±\sqrt{100}$ $x=-10±10$ $x=10+10$ or $x=10-10$ $x=20$ or $x=0$

Work Step by Step

Given: $x^2+20x$ The coefficient of the $x$-term is $20$. Half of $20$ is $10$, and $(10)^2 = 100$ Thus, add $100$ to both sides to complete the square. $x^2+20x+100=100$ Since, $a^2+2ab+b^2=(a+b)^2$, the equation becomes $(x+10)^2=100$ Apply the square root property to get the value of $x$. $x+10=±\sqrt{100}$ $x=-10±10$ $x=10+10$ or $x=10-10$ $x=20$ or $x=0$
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.