Verified answer

log (3 + x) - log (x - 3) = log 3;

Log quotient rule:

log [(3+x) / (x-3)] = log 3;

Raise both sides to power of 10:

10^log [(3+x) / (x-3)] = 10^log 3;

Now solve for x:

(3+x) / (x-3) = 3;

3+x = 3x - 9;

12 = 2x;

x = 6.