Precalculus (6th Edition) Blitzer

Published by Pearson
ISBN 10: 0-13446-914-3
ISBN 13: 978-0-13446-914-0

Chapter 7 - Section 7.1 - Systems of Linear Equations in Two Variables - Concept and Vocabulary Check - Page 817: 5



Work Step by Step

When using the addition method, we need to have the opposite value of the coefficients before the variable. Thus, after we make the coefficient to be $-6$ before $y$ in the first equation, we need to multiply the second equation by a factor of $−3$, so that the coefficient of y becomes $6$ such that the variable y will be cancelled when adding the two equations. In other words, the answer is $−3$.
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.