\[\boxed{\text{653\ (653).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[\textbf{а)}\ \left( \frac{1}{3}a^{5}y^{3} \right)^{2} \cdot ( - ay)^{3} =\]
\[= - \frac{1}{9}a^{10}y^{6} \cdot a^{3}y^{3} = - \frac{1}{9}a^{13}y^{9}\]
\[\textbf{б)} - 0,1a^{4}b^{7} \cdot \left( - 30a^{2}b \right)^{2} =\]
\[= - 0,1a^{4}b^{7} \cdot 900a^{4}b^{2} =\]
\[= - 90a^{8}b^{9}\]