\[\boxed{\text{1003.}\text{\ }еуроки - ответы\ на\ пятёрку}\]
\[\textbf{а)}\frac{27}{64} - y^{12} =\]
\[= \left( \frac{3}{4} - y^{4} \right)\left( \frac{9}{16} + \frac{3}{4}y^{4} + y^{8} \right)\]
\[\textbf{б)} - x^{15} + \frac{1}{27} =\]
\[= \left( \frac{1}{3} - x^{5} \right)\left( \frac{1}{9} + \frac{1}{3}x^{5} + x^{10} \right)\]
\[\textbf{в)}\ 3\frac{3}{8}a^{15} + b^{12} = \frac{27}{8}a^{15} +\]
\[+ b^{12} = \left( \frac{3}{2}a^{5} + b^{4} \right)\]
\[\left( \frac{9}{4}a^{10} - \frac{3}{2}a^{5}b^{4} + b^{8} \right)\]
\[\textbf{г)}\ 1\frac{61}{64}x^{18} + y³ = \frac{125}{64}x^{18} +\]
\[+ y^{3} = \left( \frac{5}{4}x^{6} + y \right)\]
\[\left( \frac{25}{16}x^{12} - \frac{5}{4}x^{6}y + y^{2} \right)\]