At a unit price of $55, the quantity demanded of headphones is 1000 units. At a unit price of $85, the demand drops to 600 units. Assume demand is a linear function.

a. find the demand equation.

b. above what price will there be no demand?

c.What quantity would be demanded if the headphones were free?

a. find the demand equation.

b. above what price will there be no demand?

c.What quantity would be demanded if the headphones were free?