Precalculus: Mathematics for Calculus, 7th Edition

Published by Brooks Cole
ISBN 10: 1305071751
ISBN 13: 978-1-30507-175-9

Chapter 4 - Review - Exercises - Page 389: 58



Work Step by Step

$5^{4-x}=\dfrac{1}{125}$ Rewrite $125$ as $5^{3}$: $5^{4-x}=\dfrac{1}{5^{3}}$ Take $5^{3}$ to the numerator by changing the sign of its exponent: $5^{4-x}=5^{-3}$ If $5^{4-x}=5^{-3}$, then $4-x=-3$ $4-x=-3$ Solve for $x$: $-x=-3-4$ $-x=-7$ $x=7$
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.