posted by Anonymous .
How is the number of cars and other vehicles changing over time? You may need to model these using different types of vehicles.
i'm suppose to develop an equation for the number of cars being produced over time. i found out the number of cars that was produced every year from 1991 through 2009 but i can't seem to relate them together with an equation because the number of cars produced each year is changing sometimes it increases and in other years it decreases.
Are you allowed to use + or - (plus or minus) in your equation?