Answer
$\log_{10} .0001=-4$
Work Step by Step
$10^{-4}=.0001$
This means that $10$ must be raised to the power of -4 in order to get $.0001$.
$\log_{10} .0001=-4$ means the same.
You can help us out by revising, improving and updating this answer.
Update this answerAfter 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.