+ = 1.
Equivalently
+ = 1, which is the same as
+ = 1.
Ellipse with the center at (x,y) = (12,3).
The major axis is vertical. The ellipse is taller than wide.
The major (vertical) semi-axis has the length of a = of unit.
The minor (horizontal) semi-axis has the length of b = of unit.
The linear eccentricity is c = = = .
Having this, you can easily determine the foci of the ellipse.
The referred lesson is the part of this online textbook under the topic
"Conic sections: Ellipses. Definition, major elements and properties. Solved problems".