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 - 7.3 Systems of Linear Equations in Two Variables - Exercise Set 7.3 - Page 445: 49

Answer

The required values are,\[m=-4\ \text{and}\ b=3\]

Work Step by Step

The linear function is\[f\left( x \right)=mx+b\]where\[f\left( -2 \right)=11\]and\[f\left( 3 \right)=-9\]. Put \[x=-2\]in the given function to get the linear equation\[-2m+b=11\].Put \[x=3\]in the given function to get the linear equation\[3m+b=-9\]. Subtract the obtained equation from both RHS and LHS as follows: \[\underline{\begin{align} & -2m+b=11 \\ & -3m-b=+9 \end{align}}\] \[\begin{align} & -5m\ \ \ \ \ \ \ =20 \\ & m=-4 \end{align}\] Put\[m=-4\]in\[-2m+b=11\]to get: \[\begin{align} & -2\left( -4 \right)+b=11 \\ & -8+b=11 \\ & b=3 \end{align}\] To verify put\[m=-4\]and \[b=3\] in\[3m+b=-9\]as follows: \[\begin{align} & 3\left( -4 \right)+3=-9 \\ & -12+3=-9 \\ & -9=-9 \end{align}\] RHS\[=\]LHS Hence verified. Hence, the\[m=-4\ \text{and}\ b=3\].
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.