Question 741584
Seeing how those pairs of points are arranged, the first pair shows you the major axis and the second pair shows you the minor axis.  The major axis give you your "a", and you can see from plotting the two pair of points that you have a term, y^2/a^2, and that {{{a=(5-(-1))/2=3}}}.  Your term with the y is then {{{y^2/3^2}}}.


Your minor axis is the shorter segment defined by the other pair of points, and length of minor axis is 2, meaning distance from center to either point is 1, so you have b=1.


Ellipse is {{{x^2/1+y^2/9=1}}}