The equation of the ellipse that has a center at
(
2
,
4
)
, a focus at
(
5
,
4
)
, and a vertex at
(
7
,
4
)
, is
(
x
−
C
)
2
A
2
+
(
y
−
D
)
2
B
2
=
1

where
A
=


B
=


C
=


D
=