How Can Integral Substitutions Simplify \(\int \frac{dx}{x^{2} e^{-2/x}}\)?

[Kuno]

Homework Statement

$$\int \frac{dx}{x^{2} e^{\frac{-2}{x}}}$$

The Attempt at a Solution

I'm not sure where to begin.

 

[neutrino]

Have you tried any substitutions?

 

[FrogPad]

What happens if you make a substitution, say: $u = =\frac{2}{x}$ ?

 

[Kuno]

I got it with u = -2/x, thanks. I'm not sure why I didn't do that in the first place.