Ellipse

A ray of light through (2, 1) is reflected at a point P on the y-axis and then passes through the point (5, 3). If this reflected ray is the directrix of an ellipse with eccentricity \({1 \over 3}\) and the distance of the nearer focus from this directrix is \({8 \over {\sqrt {53} }}\), then the equation of the other directrix can be :