4/(x²-10x+25) - 10/(x²-25) = 1/(x+5) , x≠-5,x≠5
4/(x-5)² - 10/(x+5)(x-5) = 1/(x+5) /.(x-5)²(x+5)
4(x+5)-10(x-5) = (x-5)²
4x+20-10x+50=x²-10x+25
-6x+70=x²-10x+25
x²-4x-45=0, D=16+180=196, √D=√196=14
x1=(4+14)/2=18/2=9
x2=(4-14)/2=-10/2=-5 , net rešeniem
Otvet: x=9