"I got 0" is not a meaningful statement. Doe what did you "get 0"? Please write it discernable notation. Which variable did you eliminate? Either x = 0 or y = 0 or both x = y = 0 might be a good answer. If you get 0 = 0, that's a different story. If you get 0 = 12, that is yet another different story.
So, exactly what did you do and what happened?