9x^8+x^2/3
=(x^2/3)*(27x^6+1)
=(x^2/3)*[(3x^2)^3+1^3]
=(x^2/3)(3x^2+1)(9x^4-3x^2+1)
=x^2*(3x^2+1)(9x^4-3x^2+1)/3.