This is not easily done with elementary methods. That is why you can not find the right substitution.
It can be represented by the exponential integral, Ei.
Which is represented by
Thanks for this but I should have added that it is not to be done with exponential integrals, or I don't think so because it has never been and will never be discussed in the course I'm taking.
I was wondering about some kind of amazing trick. There must be one. Our problems are always done so that there is an amazing trick.