Bài giải :
( Tính $\frac{{{72}^{3}}{{.54}^{2}}}{{{108}^{4}}}=$ ………. ? )
$\frac{{{72}^{3}}{{.54}^{2}}}{{{108}^{4}}}=\frac{{{\left( {{2}^{3}}{{.3}^{2}} \right)}^{3}}.{{\left( {{2.3}^{3}} \right)}^{2}}}{{{\left( {{2}^{2}}{{.3}^{3}} \right)}^{4}}}=\frac{{{2}^{9}}{{.3}^{6}}{{.2}^{2}}{{.3}^{6}}}{{{2}^{8}}{{.3}^{12}}}=\frac{{{2}^{11}}{{.3}^{12}}}{{{2}^{8}}{{.3}^{12}}}={{2}^{3}}=8$