y=(x+1/x+1/x^2)(x^2+x+1)=
=x^3+x^2+x+x+1+1/x+1+1/x+1/x^2=
=x^3+x^2+2x+2+2/x+2/x^2
y ' = 3x^2+2x+2-2/x^2-4/x^3
y=(x+1/x+1/x^2)(x^2+x+1)=
=x^3+x^2+x+x+1+1/x+1+1/x+1/x^2=
=x^3+x^2+2x+2+2/x+2/x^2
y ' = 3x^2+2x+2-2/x^2-4/x^3