[x(x^2-2x+3)-3x]/[(1/2)x^2]
=x(x^2-2x)/[(1/2)x^2]
=(x-2)/(1/2)
=2x-4(x^2+x)^2-(x+1)^2(x^2+x)^2-(x+1)^2

=(x^2+x+x+1)(x^2+x-x-1)
=(x^2+2x+1)(x^2-1)
=(x+1)^3.(x-1)