\[\boxed{\text{977.}\text{\ }еуроки - ответы\ на\ пятёрку}\]
\[\textbf{а)}\ \left( a^{2} + 3b^{3} \right)^{3} = a^{6} + 9a^{4}b³ +\]
\[+ 27a^{2}b^{6} + 27b^{9}\]
\[\textbf{б)}\ (1 - 2xy)^{4} = 1 +\]
\[+ 4 \cdot ( - 2xy) + 6 \cdot ( - 2xy)^{2} +\]
\[+ 4 \cdot ( - 2xy)^{3} + (2xy)^{4} =\]
\[= \ 1 - 8xy + 24x^{2}y^{2} -\]
\[- 32x^{3}y^{3} + 16x^{4}y^{4}\]