# Integral substitutions question help

1. Jun 23, 2007

### Kuno

1. The problem statement, all variables and given/known data
$$\int \frac{dx}{x^{2} e^{\frac{-2}{x}}}$$

3. The attempt at a solution
I'm not sure where to begin.

Last edited: Jun 23, 2007
2. Jun 23, 2007

### neutrino

Have you tried any substitutions?

3. Jun 23, 2007

### FrogPad

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

4. Jun 23, 2007

### Kuno

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

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