if we plot those 4 points, the two vertices and the two foci, we'll notice that they're all colinear vertically, namely making a vertical line, which in short means is a vertical ellipse, which means the "a" component will go under the fraction with the "y" above.
the half-way between the vertices lands on (-2, -3), thus that is our center.
the distance from one vertex to the other is 10 units, meaning a = 5.
the distance from the center to either foci is 4 units, meaning c = 4.
what's "b" anyway?
Check the picture below.
