10/(25-x²) -1/(5+x)-x/(x-5)=10/(5-x)(5+x) - 1/(5+x)+ x/(5-x)=(10-5+x+5x+x²)/(5-x)(5+x)= =(x²+6x+5)/(5-x)(5+x)=((x+1)(x+5)/(5-x)(5+x)=(x+1)/(5-x)