(25y^2-5y+1)*5y-5(1-4y^2)
=125y^3-25y^2+5y+20y^2-5
=125y^3-5y^2+5y-5
=125*(2/5)^3-5*(2/5)^2+5*(2/5)-5
=8-(4/5)+2-5
=21/5