7. A Company finds that its sales since the company started in 2000 can be modelled by the function s(t)=20t^2+800t+300/8t^2+10t+100, where S is the total sales, in millions of dollars, and t is the number of years since 2000.

(a) Calculate the years when the sales are 9 million, algebraically. (3 marks)

(b) After many years, what does the model predict sales will be? (1 mark)