College Algebra (11th Edition)

Published by Pearson
ISBN 10: 0321671791
ISBN 13: 978-0-32167-179-0

Chapter 4 - Section 4.5 - Exponential and Logarithmic Equations - 4.5 Exercises - Page 446: 11

Answer

$x\approx-1.710$

Work Step by Step

$\bf{\text{Solution Outline:}}$ To solve the given equation, $ 4^{x-1}=3^{2x} ,$ take the logarithm of both sides. Then use the properties of logarithms and the properties of equality to isolate the variable. $\bf{\text{Solution Details:}}$ Taking the logarithm of both sides, the equation above is equivalent to \begin{array}{l}\require{cancel} \log4^{x-1}=\log3^{2x} .\end{array} Using the Power Rule of Logarithms, which is given by $\log_b x^y=y\log_bx,$ the expression above is equivalent to \begin{array}{l}\require{cancel} (x-1)\log4=2x\log3 .\end{array} Using the Distributive Property which is given by $a(b+c)=ab+ac,$ the expression above is equivalent to \begin{array}{l}\require{cancel} x(\log4)-1(\log4)=2x\log3 \\\\ x\log4-\log4=2x\log3 .\end{array} Using the properties of equality to isolate the variable, the equation above is equivalent to \begin{array}{l}\require{cancel} x\log4-2x\log3=\log4 \\\\ x(\log4-2\log3)=\log4 \\\\ x=\dfrac{\log4}{\log4-2\log3} \\\\ x\approx-1.710 .\end{array}
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.