Question 439714
Dividing both sides by 225 we get:{{{x^2/(15/3)^2+y^2/(15/5)^2=225/225}}},

simplifying we get:{{{x^2/5^2+y^2/3^2=1}}}, which represent the equation of an   

ellipse centered at (0, 0).

The coordinates of the vertices are:(5, 0), (-5, 0) and coordinates of the foci

are:( {{{c^2+a^2-b^2=25-9=16}}} => c=+or-4.), (4, 0) and (-4, 0).

Done.