Answer:
Vertex form is y=(x-5)^2-43
Step-by-step explanation:
Given expression: x^2-10x-18
Take half of b:
-10/2=-5
Square the result:
-5^2=25
Add and subtract into original expression:
x^2-10x+25-25-18
Factor and simplify:
(x^2-10x+25)-25-18
(x-5)^2-25-18
(x-5)^2-43
So the vertex form is y=(x-5)^2-43