2/(1 + x) is the answer
To solve we can use chain rule and the knowledge that the derivative of the natural log is 1/x
So we have 1/((1 + x) / (1 - x))
Multiplied by the derivative of the stuff inside the natural log
We solve the derivative of what is inside the natural log and we get 2/(1 - x)
Then we can simplify this:
(2 / (1 - x)) / ((1 + x) / (1 - x))
Canceling the 1 - x term
To get the final answer of 2/(1 - x)
I hope this helps :)
I can help with the algebra simplifying if you want also :))