5/(x^2+5x)+(x+15)/(25-x^2)=5/(x(x+5))+(x+15)/((5-x)(x+5))=5/(x(x+5))-(x+15)/((x-5)(x+5))=(5x-25-x^2-15x)/(х(х-5)(х+5))=(-х^2-10х-25)/(х(х-5)(х+5))=-(х^2+10х+25)/(х(х-5)(х+5))=-(х+5)^2/(х(х-5)(х+5))=-(х+5)/(х(х-5)) при х≠-5
Ответ: -(х+5)/(х(х-5)) при х≠-5