Question 743730
You can get the {{{2*a}}} and the center point from the major axis information.  From -9 to +3 is {{{12=2*a}}}, so {{{highlight(a=6)}}}.  You can find from the two endpoints of the axis that the 'a' goes with the x, being horizontal major axis.  


The center is on the line y=4 and is the midpoint of x at -9 and +3, so {{{highlight((-9+3)/2=-3)}}}.  Center is (-3,4).


Up to this, you have {{{(1/36)(x+3)^2+(1/(b)^2)(y-4)^2=1}}}.
To finish, you want to use (-3,8) to find b.