Answer
true
Work Step by Step
Using the Change-of-Base Property,
$\displaystyle \log_{b}M=\frac{\log_{a}M}{\log_{a}b}$,
we want to change the base
of the logarithm on the LHS from 3 to 7:
b=3, M=7, a=7:
$LHS=\displaystyle \log_{3}7=\frac{\log_{7}7}{\log_{7}3}$ = ...
... the numerator equals 1, by the basic property $\log_{b}b=1$,
$=\displaystyle \frac{1}{\log_{7}3}=RHS,$
so the problem statement is true.