(y-16y^1/2) /5y^1/4+20
(y-16y^(1/2)) /(5y^(1/4)+20)=y^(1/2)(y^(1/2)-16) /(5(y^(1/4)+4))=y^(1/2)(y^(1/4)-4)(y^(1/4)+4)/(5(y^(1/4)+4))=1/5 y^(1/2)(y^(1/4)-4)