\[\boxed{\text{477\ (477).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[\textbf{а)}\ 9b^{2}c^{2} = (3bc)^{2}\text{\ \ }\]
\[100m^{2}n^{6} = \left( 10mn^{3} \right)^{2}.\]
\[\textbf{б)} - a^{3}b^{6} = \left( - ab^{2} \right)^{3}\]
\[- 27x^{6}b^{9} = \left( - 3x^{2}b^{3} \right)^{3}\text{.\ }\]