Consider the parabola given by the equation:

$\displaystyle {f{{\left({x}\right)}}}={x}^{{2}}-{6}{x}-{9}$

Find the following for this parabola:

A) The value of $\displaystyle {f{{\left(-{1}\right)}}}$:

B) The vertex = (,)

C) The $\displaystyle {y}$ intercept is the point (0,)

D) Find the two values of $\displaystyle {x}$ that make $\displaystyle {f{{\left({x}\right)}}}={0}$. Round your answers to two decimal places. Write the values as a list, separated by commas:
$\displaystyle {x}=$