$\frac{\left(6x^{3}-L\right)^{9}}{19683x^{18}}$

$512x^{9}-768Lx^{6}+512L^{2}x^{3}-\frac{1792L^{3}}{9}+\frac{448L^{4}}{9x^{3}}-\frac{224L^{5}}{27x^{6}}+\frac{224L^{6}}{243x^{9}}-\frac{16L^{7}}{243x^{12}}+\frac{2L^{8}}{729x^{15}}-\frac{L^{9}}{19683x^{18}}$