Ellipse center (0,0) so its eqn is x^2/a^2 + y^2/b^2 = 1 major axis is horizontal n length 18 so at y=0, x=+/-18 a=18 minor axis is vertical n length 2 so at x=0, y=+/-2 b=2
this is the answer, its pretty simple. I'm not sure the mathematical procedures but if you plug in 7 you get 49. Then all you got to do is subtract by 7, because the question states the number is the same. So basically,