What are the coordinates of the vertex of y x2 - 4x - 5?

Y = X2 - 4X - 5

set to zero

X2 - 4X - 5 = 0

X2 - 4X = 5

halve the linear term ( - 4 ) then square it and add that result to both sides

X2 - 4X + 4 = 5 + 4

factor on the left and gather terms together on the right

(X - 2)2 = 9

(X - 2)2 - 9 = 0

==============vertex form

(2, - 9)

======vertex