Ответ:(((y+1)/y³-4y²+4y-1))-((y-1)/y³-2y²-2y+1)))/(4/y²-3y+1)=(((y+1)/((y-1)(y²+y+1)-4y(y-1)))-(((y-1)/((y+1)(y²-y+1)-2y(y+1)))•((y²-3y-1)/4)=(((y+1)/((y-1)(y²-3y-1)))-(((y-1)/((y+1)(y²-3y+1)))•((y²-3y+1)/4=((y+1)²(y-1)²)/(((y-1)(y+1)(y²-3y+1))•((y²-3y+1)/4)=((4y/((y-1)(y+1)))•(1/4)=y/((y-1)(y+1))=y/y²-1

Объяснение: