a)
[tex]u(x) = 2x^{3}-x^{2}+2x-1 = x^{2}(2x-1)+2x-1 = (2x-1)(x^{2}+1)[/tex]
b)
[tex]u(x) = 2x^{3}-4x^{2}+4x-2 = 2x^{3}-2 -4x^{2}+4x = 2(x^{3}-1^{3})-4x(x-1)=\\\\=2(x-1)(x^{2}+x+1)-4x(x-1) = (x-1)\cdot[2(x^{2}+x+1)-4x]=\\\\=(x-1)\cdot(2x^{2}+2x+2-4x) =2(x-1)(x^{2}+x+1)[/tex]
