convert from log form to exponent form and then solve and then convert back to log form.
log3(729) = x if and only if 3^x = 729
through iteration it was determined that x = 6
you get 3^6 = 729
this is true if and only if log3(729) = 6
you get x = 6.
it won't always be that easy because the exponent is not always an integer, so the better way is through the use of a calculator and the log base conversion formula.
log3(729) = x
convert log base to 10 or e because those are the log bases that your calculator can handle.
log base 10 is the log function key on your calculator.
log base e is the ln function key on your calculator.