Solve for x:
log(3 x - 9) = log(2 x + 6)
Subtract log(2 x + 6) from both sides:
log(3 x - 9) - log(2 x + 6) = 0
log(3 x - 9) - log(2 x + 6) = log(1/(2 x + 6)) + log(3 x - 9) = log((3 x - 9)/(2 x + 6)):
log((3 x - 9)/(2 x + 6)) = 0
Cancel logarithms by taking exp of both sides:
(3 x - 9)/(2 x + 6) = 1
Multiply both sides by 2 x + 6:
3 x - 9 = 2 x + 6
Subtract 2 x - 9 from both sides:
Answer: |x = 15