i have been stuck on this question for a week please help

From 1985 to 2000 the percent p of total music sales with a certain format is modeled by p=5.7t - 11,308 where t is the year.

(a) evaluate p for t= 1985 and t =2000
(b) use your results from part (a) to graph the equation from 1985 to 2000
(c) in what year was p = 74.9%?
(a) p = for t = 1985 round to the nearest tenth as needed
P = for t = 2000 round to the nearest tenth as needed
(C) in what year was p = 74.9%?

Question

i have been stuck on this question for a week please help

From 1985 to 2000 the percent p of total music sales with a certain format is modeled by p=5.7t - 11,308 where t is the year.

(a) evaluate p for t= 1985 and t =2000
 (b) use your results from part (a) to graph the equation from 1985 to 2000
 (c) in what year was p = 74.9%? 
(a) p =     for t = 1985 round to the nearest tenth as needed 
P =     for t = 2000 round to the nearest tenth as needed 
(C) in what year was p = 74.9%?