What is 125x9 + 64y12 written as a sum of cubes?

[tex]\bf \textit{difference and sum of cubes} \\\\ a^3+b^3 = (a+b)(a^2-ab+b^2) \\\\ a^3-b^3 = (a-b)(a^2+ab+b^2)\\\\ -------------------------------[/tex]

[tex]\bf 125x^9+64y^{12}\qquad \begin{cases} 125=5\cdot 5\cdot 5\\ \qquad 5^3\\ x^9=x^{3\cdot 3}\\ \qquad (x^3)^3\\ 64=4\cdot 4\cdot 4\\ \qquad 4^3\\ y^{12}=y^{4\cdot 3}\\ \qquad (y^4)^3 \end{cases}\implies 5^3(x^3)^3+4^3(y^4)^3 \\\\\\ (5x^3)^3+(4y^4)^3\implies [(5x^3)^2-(5x^3)(4y^4)+(4y^4)^2] \\\\\\ 25x^6-20x^3y^4+16y^8[/tex]