## College Algebra (11th Edition)

$\log_{27} 81=\dfrac{4}{3}$
Since $y=b^x$ is equivalent to $\log_b y=x,$ then the given equation, $27^{4/3}=81 ,$ is equivalent to \begin{array}{l}\require{cancel} \log_{27} 81=\dfrac{4}{3} .\end{array}