Answer
{$3$}
Work Step by Step
Step 1: $\log_{x} 81=4$
Step 2: $x^{4}=81$
Step 3: $x=\sqrt[4] {81}$
Step 4: $x=(81)^{\frac{1}{4}}$
Step 5: $x=(3^{4})^{\frac{1}{4}}$
Step 6: $x=3$
Therefore, the solution set is {$3$}.
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.