Week 9, option 1

Well actually my muddiest point came from today's video.  I can understand the whole long division thing rather well.  It seems very simple, the only problem I am seeing is the whole starting value.  From the video I have no idea how you got that number.  It was not really explained, it just appeared and you said you did some sort of formula.  I will probably be able to understand it so long as you go over it on Monday.  Again I understand how to do the long division, but I don't know how you found the x=0.  Do I just plug it into my calculator? Is there some sort of formula?  I just could not see where you got the x intercept variable.