Answer
$$-\left(x-3\right)^2+7$$
Work Step by Step
Completing the square in order to write the equation in the form $a(x-h)^2+k$, we find:
$$ -\left(x^2-6x+2+\left(-3\right)^2-\left(-3\right)^2\right) \\ -\left(\left(x-3\right)^2+2-\left(-3\right)^2\right) \\ -\left(x-3\right)^2+7$$