Thinking Mathematically (6th Edition)

Published by Pearson
ISBN 10: 0321867327
ISBN 13: 978-0-32186-732-2

Chapter 7 - Algebra: Graphs, Functions, and Linear Systems - 7.2 Linear Functions and Their Graphs - Exercise Set 7.2 - Page 431: 56

Answer

The value of y is \[-6\].

Work Step by Step

Use the formula, \[m=\frac{{{y}_{2}}-{{y}_{1}}}{{{x}_{2}}-{{x}_{1}}}\], where m is slope of the line passing through points \[\left( {{x}_{1}},{{y}_{1}} \right)\]and \[\left( {{x}_{2}},{{y}_{2}} \right)\]. Take \[\left( {{x}_{1}},{{y}_{1}} \right)=\left( -2,y \right)\] and \[\left( {{x}_{2}},{{y}_{2}} \right)=\left( 4,-4 \right)\], \[m=\frac{1}{3}\]. Slope of the line is: \[m=\frac{{{y}_{2}}-{{y}_{1}}}{{{x}_{2}}-{{x}_{1}}}\] \[\begin{align} & m=\frac{-4-y}{4-\left( -2 \right)} \\ & \frac{1}{3}=\frac{-4-y}{4+2} \\ & \frac{1}{3}=\frac{-4-y}{6} \\ & 1=\frac{-4-y}{2} \end{align}\] Apply cross-products principle: \[\begin{align} & 2=-4-y \\ & y=-4-2 \\ & y=-6 \\ \end{align}\] Thus, the value of y is \[-6\].
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.