Solve for x: log_3 67 = 2x.

By Change-Base Rule
$\dfrac{\ln 67}{\ln 3} = 2x$

$x = \dfrac{\ln 67}{2 \ln 3}$

$x = 1.9136$
 

You can also use logarithm to the base 10
$\dfrac{\log 67}{\log 3} = 2x$

$x = \dfrac{\log 67}{2 \log 3}$

$x = 1.9136$