X^2-1/x^2-4*5x+10/x+1
Х²-1/х²-4*5х+10/х+1=(х²-1)(5х+10)/(х²-4)(х+1)=(х-1)(х+1)*5(х+2)/(х-2)(х+2)(х+1)=5(х-1)/х-2=5х-5/х-2