\(\dfrac{72^3.54^2}{108^4}\)
\(=\dfrac{18^3.4^3.18^2.3^2}{18^4.6^4}\)
\(=\dfrac{18^5.2^6.3^2}{18^4.2^4.3^4}\)
\(=\dfrac{18.2^2}{3^2}\)
\(=\dfrac{9.2.2^2}{9}\)
\(=2^3=8\)
\(D=\dfrac{72^3\cdot54^2}{108^4}=\dfrac{2^9\cdot3^6\cdot2^2\cdot3^6}{2^8\cdot3^{12}}=2^3=8\)