Assuming the equations are supposed to read [tex]n^{2}[/tex]=25 , you can find the square root of both sides to find n.
[tex]\sqrt{n^{2}}=\sqrt{25} \sqrt{n^{2}}=\sqrt{36}[/tex]
The square root of 36 is 6, and the square root of 25 is 5.
n=5 and n=6
So, in Mr. Miller's class, there are 5 desks in each row.
In Mrs. Fernandez's class, there are 6 desks in each row.
Hope this helps :)