State the vertex of the graph:

y=2x-6x+9

...the 2x is squared.

y = 2x^2 -6x + 9
The vertex is where the function is a minimum. That would be where dy/dx = 4x -6 = 0
x= 3/2

If you are not familiar with calculus, then rewrite the expression

y = 2 (x^2 -3x + (3/2)^2) +9 -(3/2)^2
= 2(x - 3/2)^2 + constant
That has a minimum when x -3/2 = 0

1 answer

multiply 2 by 2