The serpentine belt broke replaced it and i broke

I had this problem, it turned out that A/C compressor had seized and wouldn't turn, because the compressor was stuck it would rip up the new belt- so you can one of two things;

replace the compressor and belt

or
get a shorter serpentine belt and bypass the A/C compressor- there are several sites that show you how to route this.- i did this being a college student, not having A/C isn't that bad

A bad belt tensioner leaving too much slack in belt causes it to break.