All your calculations are OK. There is only one step missing:

Now cancel and you'll get the given answer.

The first step is OK. Before you are going to determine the 2nd derivative simplify the term:2.I am suppose to find the 2nd derivative of (1+(1/x))^3

My work:

3(1+(1/x))^2 * -x^(-2)

-(6(-x^(-2))) * (-2x^(-3)... this was the farthest I went since I knew this was not right.

the answer was suppose to be:

(6/x^3) * (1+(1/x)) * (1+(2/x))

Can you take it from here?