Respuesta :

Answer:

Vertex:   ( 1 ,  9 )

Y-intercept:   ( 0 ,  8 )

Step-by-step explanation:

y = - (x+2) (x-4)

y = -x² + 2x + 8

Find the vertex.

x = -b/2a

x = -2/2(-1)

x = -2/-2

x = 1

y = -(1)² + 2(1) + 8

y = -1 + 2 + 8

y = 9

Find the y-intercept.

Put x as 0.

y = -(0)² + 2(0) + 8

y = 8