Quadratic Equations

Question

8) A manufacturer determines that the number of drills it can sell is given by the formula − 4p 60p 05 , where is the price of the drills in dollars and D is the number of 2 + 1 − 3 = D p drills it sells.

a) At what price will the manufacturer sell the maximum number of drills?

b) What is the maximum number of drills that can be sold?

Answer 1

Need more imfo about the "formula".