Should I sell it or use it?
 

I have had this mountain bike that i got from target about 4-5 years ago but it broke.
Should i have it fixed and use it, have it fixed and sell it and buy a new one, or sell it as is and buy a new one?

Looks like the rear derailleur is broken. Any frame damage or just the derailleur? Overall, it is a pretty cheap IMO, but depending on what you plan to use it for and what your budget is, it is usable and can most likely be fixed for much cheaper than a new bike could be gotten. If you plan to do much serious riding, I doubt it will hold up for long. If it is 7 speed and that is all that is broken, derailleurs can be had for under $15. My advice is that if you plan on doing actual mountain biking, fix it then sell it and buy a better bike if you can afford it.

Yea, I think i may have it fixed and sell it, today i looked at it that said "not for competitions bla bla bla, and off road use" I like how they put that at the end.
I think I'm gonna look into a hardtail, any suggestions on where to get a affordable one? And also, how much should I sell this bike for after getting it fixed so i know what i could gain, i was thinking 75-150.