Simplifies to ln((x2-3x-40)/(x-8)).
x2-3x-40=(x-8)(x+5), so further simplification is ln(x+5).
However, the original expression cannot be evaluated for x=8 because ln(x-8) becomes ln(0) which cannot be evaluated. Also, x+5>0, x>-5 so that ln(x+5) can be evaluated.
x2-3x-40 must be greater than zero so that the log can be evaluated. Therefore x-8>0 and x+5>0⇒x>8; or x-8<0 and x+5<0⇒x<-5, which contradicts the requirement that ln(x+5) can be evaluated.
CONCLUSION
Simplification is ln(x+5) provided that x>8.