Question 625276
The number of tickets sold each day for an upcoming performance of Handel's Messiah is given by N(x)= -0.4x^2+8x+15, where x is the number of days since the concert was first announced. 
When will daily tickets sales peak and how many tickets will be sold that day?
Tickets sales will peak ? days after the concert was first announced.
The vertex defines the peak sales:
x = -b/(2a)
x = -8/(2(-0.4))
x = -8/(-0.8)
x = 10 days
The number of tickets sold on that day will be ?
plug x=10 back into original equation:
N(10)= -0.4(10)^2+8(10)+15
N(10)= -0.4(100)+(80)+15
N(10)= -40+80+15
N(10)= 40+15
N(10)= 55 tickets