Find $\int \left(e^{\frac{x}{2}}-\frac{5}{x^2}\right)dx$ by substituion

Question

$\int \left(e^{\frac{x}{2}}-\frac{5}{x^2}\right)dx$

I am supposed to use u substitution, but I'm not sure which variable to choose as u.

Any help is appreciated, thanks!

Answer 1

Hint. You have

$$ \int e^{ax} dx=\frac 1 a e^{ax}+C, \quad a \neq 0, $$ and $$ \int \frac 1 {x^2} dx=-\frac 1 x+C $$ then use linearity of the integral.