Please help me solve this equation dealing with a parabola

Find the equation for a parabola with directrix x = -3 and Focus (1,2).

Please explain in steps if possible how to write the equation for this problem.

first - center is midpoint between directrix and focus
so locate it by plotting dir and F
It shows that the parabola opens to the left, and horizontal having its canter not at the origin
next step get its form.
center(-1, 2)

its form is
(y-k)²= 4p(x-h)

plug in center
(y-2)²= 4p(x+1)

find p
p=distant from F to V ,or V to Dir
p=2
plug p=2

(y-2)²= 8(x+1).
that is it.