1. Since the point P(8, 2) lies at the right side of the vertex the parabola opens to the right. The general equation of such a parabola is

with the vertex at V(k, h)

2. You already know that the latus rectum l = 4p which is 6 in your question.

3. You know the x-coordiante of the vertex (k = 2) and you know the coordinates of one point of the parabola. Plug in all known values:

Solve for h.

EDIT: There are two parabolas which satisfy the given conditions!