Write the equation of a parabola whose directrix is X=11.25 and focus is (6.75,6) Please Help me

Check the picture below.  So the parabola looks like so.

we know the directrix is at x = 11.25, the blue line, and we also know the focus point is at (6.75 , 6), meaning that the focus point is to the left-side of the directrix, it means is a horizontal parabola, thus the squared variable is the "y", and it also means that our "p" distance will be negative.

we know the the vertex is half-way between the directrix and the focus point, so 11.25 - 6.75 = 4.5, half that is 2.25 units, so if we move from either the focus point or the directrix, 2.25 units towards the other, we'll get the vertex, well, hmmm say 11.25 - 2.25 = 9, and the y-coordinate is of course the same as the focus point's.

now, since "p" is negative, that means p = -2.25.

b

step-by-step explanation: