Question 606686
{{{4^(3x-1)=12}}}
If you have a variable in the exponent, we always want to take logs of both sides:
{{{log(4^(3x-1))=log(12)}}}
Now we can bring down the exponent using our log rules:
{{{(3x-1)log(4)=log(12)}}}
And isolate for x 
{{{(3x-1)=log(12)/(log(4))}}}


I will leave the rest of the isolating up to you.  (Don't forget that log of a number is just a number itself, so don't let that fool you)