a)
\frac{W(x)}{P(x)}=H(x) + R(x)
W(x)=(x^2+3)(3x^2-5x+1)+\frac{x-1}{x^2+3}=\frac{(x^2+3)^2(3x^2-5x+1)+x-1}{x^2+3}=
\frac{(x^2+6x^2+9)(3x^2-5x+1)+x-1}{x^2+3}=
\frac{3x^6-5x^5+x^4+18x^4-30x^3+6x^2+27x^2-45x+9+x-1}{x^2+3}=
\frac{3x^6-5x^5+19x^4-30x^3+33x^2-44x+8}{x^2+3}=