a logarithm can be explained as the exponent that indicates to what power a number must be raised in order to obtain a given number.
therefore we can write both exponential and logarithmic expressions for an equation
[tex]\begin{gathered} y=b^x\colon exponential_-form \\ x=\log _by\colon logarithmic_-form \end{gathered}[/tex]then the logarithmic form for the equation given is
[tex]\log _516=m[/tex]