The number of tickets sold each day for an upcoming performance of Handel's Messiah is given by N(x) = -0.5x + 15x + 14, where

The number of tickets sold each day for an upcoming performance of Handel's Messiah is given by N(x) = -0.5x² + 15x + 14, where x is the number of days since the concert was first announced. When will daily ticket sales peak and how many tickets will be sold that day? Ticket sales will peak days after the concert was first announced.