A manufacture has been selling 1700 television sets a week at 480 each. A market survey indicates that for each 25 rebate offered to a buyer, the...

A manufacture has been selling 1700 television sets a week at 480 each. A market survey indicates that for each 25 rebate offered to a buyer, the number of sets sold will increase by 250 per week. a) Find the demand function , where is the number of the television sets sold per week.