Answer:
![(x^2)/(400)+(y^2)/(625)=1](https://img.qammunity.org/2020/formulas/mathematics/middle-school/4g0ku4cak6csrwrz36stgdxeztaefhbp1g.png)
Explanation:
The equation of an ellipse that has its center at the origin is given by the formula:
![(x^2)/(b^2)+(y^2)/(a^2)=1](https://img.qammunity.org/2020/formulas/mathematics/middle-school/j7pi89iww7clq4de3iymc6he8d9fxibwr9.png)
The given ellipse is 50 units high.
This means that length of the major axis is 50.
![2a=50](https://img.qammunity.org/2020/formulas/mathematics/middle-school/qqr3neu73b8z1dyrz7nndy1efby1zul55q.png)
![2\implies a=25](https://img.qammunity.org/2020/formulas/mathematics/middle-school/5roo7ccmzavh7q8hbyv5hn2ja8p1aady22.png)
The ellipse is 40 units wide.
![2b=40](https://img.qammunity.org/2020/formulas/mathematics/middle-school/si92vdu6nunu28dl1nlpocc17wn48nifyt.png)
![\implies b=20](https://img.qammunity.org/2020/formulas/mathematics/middle-school/eqsmvlbm4we4cw7sokd3kyouzp5k7hhqgg.png)
We substitute these values into the formula to get:
![(x^2)/(20^2)+(y^2)/(25^2)=1](https://img.qammunity.org/2020/formulas/mathematics/middle-school/gfb1ss2vtdf375dwa1gu0whcay0j7pg1dv.png)
![(x^2)/(400)+(y^2)/(625)=1](https://img.qammunity.org/2020/formulas/mathematics/middle-school/4g0ku4cak6csrwrz36stgdxeztaefhbp1g.png)