Integral with exponential function

[matteo86bo]

Hi everyone,
here is this integral I can't find solution:

$$\int_0^\infty \frac{x e^{-x}}{A+Bx} dx$$

A and B are constants.

I'm going crazy, I don't think there is even an analytical solution.

 

[Char. Limit]

You're right, it's not analytic. However, the solution can be expressed in terms of the exponental integral function Ei(z).

http://en.wikipedia.org/wiki/Exponential_integral

Will that help?