\[\boxed{\text{1114.}\text{\ }еуроки - ответы\ на\ пятёрку}\]
\[\textbf{а)}\ 2x(8x - 1) - (4x + 1)^{2} =\]
\[= 16x^{2} - 2x -\]
\[- \left( 16x^{2} + 8x + 1 \right) =\]
\[= 16x^{2} - 2x - 16x^{2} - 8x -\]
\[- 1 = - 10x - 1\]
\[\textbf{б)}\ 4 \cdot (3y - 1)^{2} - 18y(2y - 1) =\]
\[= 4 \cdot \left( 9y^{2} - 6y + 1 \right) - 36y^{2} +\]
\[+ 18y =\]
\[= 36y^{2} - 24y + 4 - 36y^{2} +\]
\[+ 18y = - 6y + 4\]