Answer:
(9-7)
Step-by-step explanation:
1st
Vertex
we have
f(x)=x²-18x+88
let
y=x²-18x+88
comparing above equation with ax²+bx+c
we get
a=1
b=-18
c=88
now
vertex(x,y)=(-b/2a,f(-b/2a))
x=(18/2×1)=9
y=f(9)=9²-18×9+88=7
SO
VERTEX(X,Y)=(9,7)
