You can
put this solution on YOUR website!
There is no solution.
log (-x) + log (3) = log (2x-15)
log[(-x)(3)] = log(2x-15)
log(-3x) = log(2x-15)
Since the logs are equal, what they are the logs
of are also equal:
-3x = 2x - 15
-5x = -15
x = 3
However when we try to check:
log (-x) + log (3) = log (2x-15)
log(-3) + log(3) = log(2·3 - 15)
log(-3) is undefined. Logs cannot be
taken of 0 or negative numbers, only of
positive numbers, so the solution 3 is
extraneous.
log(-3) + log(3) = log(6-15)
log(-3) + log(3) = log(-9)
There is no solution.
Of course your answer of 5
does not check either, but you
must have solved it wrong to have
gotten 5 instead of 3.
Edwin
