Suppose x represents the number of cameras sold and y represents the number of years since 2000. Then the number of digital cameras sold each year since 2000, in millions, can be modeled by the equation y=12.5x+10.9. The number of film cameras sold each year since 2000, in millions, can be modeled by the equation y=-9.1+78.8. What are the domain and range of the functions in this situation?