Question 891530

Solve the logarithmic equation. (Enter your answers as a comma-separated list. If there is no solution, enter NO SOLUTION.)

ln x + ln (x-4) = ln 117
<pre>
ln x + ln (x - 4) = ln 117
x(x - 4) = 117
{{{x^2 - 4x - 117 = 0}}}
(x - 13)(x + 9) = 0
{{{highlight_green(x = 13)}}}                 or                  x = - 9 (ignore, as this is an EXTRANEOUS solution)