uekmyfhfp (x^2 - 25) /(x^2 - 10 x + 25) =(x^2 - 5^2) / (x^2 - 2 *x *5 + 5^2) =
=(x-5)(x+5) / (x+5)^2 = (x-5) /(x+5)

egorkaaa .................................