\[\boxed{\text{478\ (478).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[\textbf{а)}\ 16x^{6} = \left( 4x^{3} \right)^{2}\ \]
\[49m^{2}n^{4} = \left( 7mn^{2} \right)^{2}\ \]
\[m^{8} = \left( m^{4} \right)^{2}.\]
\[\textbf{б)}\ a^{9} = \left( a^{3} \right)^{3}\]
\[- 8m^{3} = ( - 2m)^{3}\ \]
\[1000x^{3}y^{6} = \left( 10xy^{2} \right)^{3}\text{.\ }\]