Question 604590
y= -6.25x²+ 150x + 7200
.
The x-value of the vertex is at:
x = -b/(2a)  (from the "quadratic formula" w/o the radical)
x = -150/(2(-6.25)
x = -150/(-12.5)
x = 150/12.5
x = 12
.
To find the y-value, plug the above back into the equation:
y= -6.25x²+ 150x + 7200
y= -6.25(12)²+ 150(12) + 7200
y= 8100