Question 1193718
<font color=black size=3>
Answer: <font color=red>(-9, -3) and (4, 7)</font>


Explanation:


Plot the two given points on the xy plane.
Then draw horizontal and vertical lines through each point.
You should have four lines total. These lines will form a rectangle.
The intersection points produce the four vertices of the rectangle, two of which are the given points. The other two are the answer points.


Graph:
<img width="40%" src = "https://i.imgur.com/a2oxzYa.png">
I used GeoGebra to make the graph. Desmos is another good option. Both apps are free.
The given points are in blue, while the answer points are in red.


Side note: infinitely many other rectangles are possible if we allow the rectangle to rotate; however, I have a feeling your teacher may want to keep things simple and stick to the configuration shown above.
</font>