Intermediate Algebra for College Students (7th Edition)

Published by Pearson
ISBN 10: 0-13417-894-7
ISBN 13: 978-0-13417-894-3

Chapter 4 - Section 4.5 - Linear Programming - Review Exercises - Page 309: 28

Answer

$\left \{-4,-\frac{6}{11}\right \}$.

Work Step by Step

$\Rightarrow |4x-3|=|7x+9|$ Rewrite the equation without absolute value bars. $\Rightarrow 4x-3= 7x+9 $. or $ 4x-3 =-\left ( 7x+9 \right ) $. Clear the parentheses. $\Rightarrow 4x-3= 7x+9 $. or $ 4x-3 =-7x-9 $. Add $3$ to both sides of each equation. $\Rightarrow 4x-3+3= 7x+9+3 $. or $ 4x-3+3 =-7x-9+3 $. Simplify. $\Rightarrow 4x= 7x+12 $. or $ 4x =-7x-6 $. Subtract $7x$ from both sides of the first equation and add $7x$ to both sides of the second equation. $\Rightarrow 4x-7x= 7x+12-7x $. or $ 4x+7x =-7x-6+7x $. Simplify. $\Rightarrow -3x= 12 $. or $ 11x =-6 $. Isolate $x$ form both sides of each equation. $\Rightarrow x= \frac{12}{-3} $. or $ x =\frac{-6}{11} $. Simplify. $\Rightarrow x=-4 $. or $ x =-\frac{6}{11} $. Check $x=-4$ $\Rightarrow |4(-4)-3|=|7(-4)+9|$ $\Rightarrow |-16-3|=|-28+9|$ $\Rightarrow |-19|=|-19|$ $\Rightarrow 19=19$ True. Check $x=-4$ $\Rightarrow |4(-\frac{6}{11})-3|=|7(-\frac{6}{11})+9|$ $\Rightarrow |-\frac{24}{11}-3|=|-\frac{42}{11}+9|$ $\Rightarrow |\frac{-24-33}{11}|=|\frac{-42+99}{11}|$ $\Rightarrow |\frac{-57}{11}|=|\frac{-57}{11}|$ $\Rightarrow \frac{57}{11}=\frac{57}{11}$ True. Hence, the solution set is $\left \{-4,-\frac{6}{11}\right \}$.
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.