What is the vertex form of $y= x^2-6x-21$ ?

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Answer 1 · 2016-03-22T14:25:42

$y = (x - 3)^2 - 30$

x-coordinate of vertex:
$x = -b/(2a) = 6/2 = 3$
y-coordinate of vertex:
$y (3) = 9 - 18 - 21 = - 30$
Vertex form: $y = (x - 3)^2 - 30$

What is the vertex form of y= x^2-6x-21 y= x^2-6x-21 ?