The equation of an ellipse:
a2(x−h)2+b2(y−k)2=1
(h,k) represents the center. a represents the length from the center to one of the points in the horizontal direction.
b represents the distance from the center to a point directly above or below. Based on the graph,
(h,k)=(2,−3)
a=3
b=5
(3)2(x−2)2+(5)2(y−(−3))2=1
9(x−2)2+25(y+3)2=1