
RAFAH A. answered 02/06/21
Former College Instructor, Calculus and Algebra Tutor
∫ ln x / ( x + x ln) dx = ∫ ln x / x(1 + ln x) dx
Let u = ln x , du = 1/x dx
∫ ln x / x(1 + ln x) dx = ∫ u / ( 1+u) du
= ∫( u +1 - 1) / ( 1+u) du , adding 1 and subtracting 1 from the numerator
= ∫ u + 1 / (1+u) - 1/ ( 1+u) du
= ∫ 1 - 1/ ( 1+u) du
= u - ln (1+u)
= ln x - ln ( 1+ ln x )
I hope all the steps are clear . if some thing not clear you can ask.