the picture above is the questions and the other picture is the correct answears. i need help how solve the problems and showing how i come to the solutions.

5. A marketing research company has polled potential buyers of a new type of MP3 player and found that if the cost of the player is $35.00 then there should be approximately 4,000,000 buyers nationally and that if the cost of the player is $70.00 then there should be approximately 2,000,000 buyers nationally. The manufacturer of the new player is willing to sell these at a price of $80.00 if 5,000,000 of the play- ers can be sold, but would sell these for $40.00 if only 2,000,000 could be sold. (a) What is the demand equation? (Hint: Calculate the slope and then use the Point-Slope form of a linear equation.) (b) Approximately how many buyers would buy this new player if its price was $50.00? (c) What is the supply equation? (Hint: Calculate the slope and then use the Point-Slope form of a linear equation.) (d) What price would the manufacturer request if there were 4,400,000 players available for sale? (e) What is the equilibrium point for this market based on the research company's data? 5. a. p= 9 + 105 400000 b. 3,142,857 c. 75000p = q + 1000000 d. $72 e. price = $53, quantity = 2,972,973