College Algebra 7th Edition

Published by Brooks Cole
ISBN 10: 1305115546
ISBN 13: 978-1-30511-554-5

Chapter 4, Exponential and Logarithmic Functions - Section 4.5 - Exponential and Logarithmic Functions - 4.5 Exercises - Page 404: 20


(a) $t=\frac{\ln 5}{10\ln\frac{11}{8}}$ (b) $t\approx 0.505391$

Work Step by Step

(a) We are given: $10(1.375)^{10t}=50$ $10(\frac{11}{8})^{10t}=50$ $(\frac{11}{8})^{10t}=\frac{50}{10}=5$ We take the natural log of both sides and use log rules to simplify: $10t\ln\frac{11}{8}=\ln 5$ $t=\frac{\ln 5}{10\ln\frac{11}{8}}$ (b) We use a calculator to solve: $t\approx 0.505391$
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.