The quantity demanded of a DVD player is 3000 when the price is $485. For each decrease in price of $20, the
quantity demanded increases by 250 units. The suppliers of the DVD player will not supply any units if the unit price is $300 or lower, but at a unit price of $525, they will make available 2500 units on the market. Assume the supply and demand functions are both linear.
How can I find the demand equation, supply equation and the market equilibrium ?