How To fix FacebookSDK merge error in androidmanifest.xml ?

Hey guys! How are you doing ? I´m almost finishing my first app. And it´s basically a trivia game. But i need Facebook SDK to do a rank with the users friends. But when i started building it for android i receive this error:

I´m one week trying to solve this, and i´ve read all posts that talsk about it, but i did not understand how can i solve this. Can someome guive me a hint of what to do ? Thanks!