\[\boxed{\text{785\ (785).\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[1) - \frac{9}{64}n^{6} - 3mn^{5} - 16m^{2}n^{4} =\]
\[= - \left( \frac{9}{64}n^{6} + 3nm^{5} + 16m^{2}n^{4} \right) =\]
\[= - \left( \frac{3}{8}n^{3} + 4mn^{2} \right)^{2}\]
\[2)\ 20z² + 3xy - 15xz - 4yz =\]
\[= \left( 20z^{2} - 4yz \right) + (3xy - 15xz) =\]
\[= 4z(5z - y) + 3x(y - 5z) =\]
\[= (5z - y)(4z - 3x)\]
\[3)\ 0,027a^{12} + b^{9} =\]