Also, please show some effort. You must have some ideas .... Post what you can do or have tried and make it clear where you get stuck.
I will answer the first by saying that you make the substitution u = 1/x. In fact, several of them are done using the method commonly called u-substitution. I suggest you review class notes or textbook. Ideally, when/if you re-post in the way advised in the above link, you will at least group them in threads according to what you think will be the required technique.