d)
W(x)=x^3-x^2+x-1=x^2(x-1)+(x-1)=(x^2+1)(x-1)
e)
W(x)=4x^3+4x^2-x-1=4x^2(x+1)-(x+1)=(4x^2-1)(x+1)=(2x-1)(2x+1)(x+1)
f)
W(x)=-9x^3-18x^2+x+2=-9x^2(x+2)+(x+2)=(1-9x^2)(x+2)=(1+3x)(1-3x)(x+2)
g)
W(x)=-3x^3-4x^2+12x+16=-x^2(3x+4)+4(3x+4)=(4-x^2)(3x+4)=(2-x) (2+x)(3x+4)
zastosowano wzory skróconego mnożenia
a^2-b^2=(a-b)(a+b)