A graph using y=mx+b would include a positive or negative line (slope) and a y-intercept. If there is a y-intercept between 1 & infinity then the line will not start on the origin. y=mx+b doesnt have to include a y-intercept though. It can include a y-intecept of 0. This would mean that the line would start on the origin. y=mx+b will ALWAYS be a straight line.
