Answer:
Step-by-step explanation:
x^2 -9x + 20 =0 factors to
(x-5)(x-4) = 0 which shows the zeroes are at x = 5 and 4
the x value of the vertex is exactly in between at 4.5
use this value in the quadratic to calculate 'y'
y = (4.5)^2 - 9( 4.5) + 20 = - 1/4
Vertex is at (4.5, - 1/4)
