Hello,
If the question is simplify then
we suppose x not equal to 5 and x not equal to -5
[tex]\dfrac{x^2-10x+25}{(x-5)(x+5)} \\\\=\dfrac{(x-5)^2}{(x-5)(x+5)} \\\\=\dfrac{x-5}{x+5} \\\\[/tex]
else
if the question is to find the euclidian 's quotient then
[tex]\dfrac{x^2-10x+25}{(x-5)(x+5)} \\\\= 1 + \dfrac{-10x+30}{x^2-25} \\\\=1-\frac{10}{x+5} \\[/tex]
euclian's quotient is 1
remainder is -10/(x+5)