Intermediate Algebra (6th Edition)

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

Chapter 5 - Section 5.3 - Polynomials and Polynomial Functions - Graphing Calculator Explorations - Page 278: 4

Answer

$-7.9x^2+20.3x-7.8$

Work Step by Step

Removing the parenthesis and then combining like terms, the given expression, $ (-4.8x^2+12.5x-7.8)-(3.1x^2-7.8x) ,$ is equivalent to \begin{array}{l}\require{cancel} -4.8x^2+12.5x-7.8-3.1x^2+7.8x \\= (-4.8x^2-3.1x^2)+(12.5x+7.8x)-7.8 \\= -7.9x^2+20.3x-7.8 .\end{array} Let \begin{array}{l}\require{cancel}Y_1= (-4.8x^2+12.5x-7.8)-(3.1x^2-7.8x) ,\\Y_2= -7.9x^2+20.3x-7.8 .\end{array} Using a graphing calculator, the graphs of $Y_1$ (dotted graph) and $Y_2$ (solid graph) are shown below. Since the graphs overlap, then $Y_2$ is the correct simplification of $Y_1.$
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.