Intermediate Algebra (6th Edition)

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

Chapter 2 - Section 2.4 - Linear Inequalities and Problem Solving - Exercise Set - Page 87: 76

Answer

greater than $200$ calls

Work Step by Step

Let $x$ be the number of calls per month. Plan 1 is more economical than Plan 2 if Plan 2 is greater than Plan 1. That is, \begin{array}{l}\require{cancel} 13+0.06x\gt25 .\end{array} Using the properties of inequality, then \begin{array}{l}\require{cancel} 0.06x\gt25-13 \\\\ 0.06x\gt12 \\\\ x\gt\dfrac{12}{0.06} \\\\ x\gt200 .\end{array} Hence, if there are $\text{ greater than $200$ calls ,}$ Plan 1 is more economical than Plan 2.
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.