Question

Express 3^2 = x as a logarithmic equation.

Answer 1

Taking the log of both sides of the equation, you have
$2\log(3)=\log(x)$
Dividing by log(3), this looks like the change of base formula.
$\log_a(b)=\dfrac{\log(b)}{\log(a)}$

That is, division by log(3) gives
$2=\dfrac{\log(x)}{\log(3)}\\\\2=log_3(x)$

This apparently matches your first choice:
  log3(x) = 2