Bad rep from friends

Hi I'm in a bit of a pickle with my friends, firstly in my 'friendship group' they dont get along with one girl who is in the group but im still friends with her and secondly my best friend ( not the one who they dont like) seems to only talk to me when she wants help or has no one else to talk to and she is very unmotivated and i feel as though it is rubbing off on me. She always tries to make herself the more smarter one and calls me stupid and dumb, sometimes we're ok and laughing our heads off.. but she is distracting in class, and whenever i move she always follows. I also think that just because im friends with her the teachers think that im 'bad' too.

Sorry for the long rant.. any tips or advice on what to do.

-from a worried teen

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