how are you?i need one help and please give me some hint to solve it,namely we should construct equation of such ellipse,focuses of which are on the axis of abscisa and are symmetrical to origin,if distance between focus is equal to $4$ and semi-major axis is equal to $5$,generally we know that equation of ellipse is like
$$\left(\frac xa\right)^2 + \left(\frac yb\right)^2 = 1$$ where $a$ and $b$ are major and minor axes,but i dont know how to continue,so please help me.
