$\begin{array}{l}
a)\,\,{20^8}{.4^8} = {\left( {20.4} \right)^8} = {80^8} = \frac{{{{80}^8}}}{1}.\\
b)\,\,{10^6}:{2^6} = {\left( {\frac{{10}}{2}} \right)^6} = {5^6} = \frac{{{5^6}}}{1}.\\
c)\,\,{5^4}{.2^8} = {5^4}.{\left( {{2^2}} \right)^4} = {5^4}{.4^4} = {\left( {5.4} \right)^4} = {20^4} = \frac{{{{20}^4}}}{1}.\\
d)\,\,{7^8}{.9^4} = {\left( {{7^2}} \right)^4}{.9^4} = {49^4}{.9^4} = {\left( {49.9} \right)^4} = {441^4} = \frac{{{{441}^4}}}{1}\\
e)\,\,{27^4}:{25^6} = {\left( {{3^3}} \right)^4}:{\left( {{5^2}} \right)^6} = {3^{12}}:{5^{12}} = {\left( {\frac{3}{5}} \right)^{12}}.
\end{array}$
