2/x^2+10x+25 - 10/25-x^2 = 1/x-5
2/(x+5)^2 - 10/(5-x)(5+x) = 1/(x-5)
2/(x+5)^2 - 10/(5-x)(5+x) = -1/(5-x)
Общий знаменатель:
(x+5)^2(5-x)
2(x+5)(5-x) - 10(5+x) = -1(x+5)^2
2(5-x)(5+x) - 50 - 10x = -1 (x^2 + 10x +25)
2(25-x^2) - 50 - 10x = -x^2 - 10x - 25
50-2x^2 - 50 - 10x + x^2 + 10x + 25 = 0
-x^2 + 25 = 0/*-1
x^2-25 = 0
(x-5)(x+5)
x = 5
x = -5
Ответ: 5 и -5