\[\boxed{\text{1014.\ }\text{еуроки}\text{-}\text{ответы}\text{\ }\text{на}\text{\ }\text{пятёрку}}\]
\[\textbf{а)}\ (6y - 1)(y + 2) <\]
\[< (3y + 4)(2y + 1)\]
\[6y^{2} + 12y - y - 2 < 6y^{2} +\]
\[+ 3y + 8y + 4\]
\[11y - 11y < 4 + 2\]
\[0 < 6 \Longrightarrow верно\ при\]
\[\ любом\ y:\ \ ч.т.д.\]
\[\textbf{б)}\ (3y - 1)(2y + 1) >\]
\[> (2y - 1)(2 + 3y)\]
\[6y^{2} + 3y - 2y - 1 > 4y +\]
\[+ 6y^{2} - 2 - 3y\]
\[y - y > - 2 + 1\]
\[0 > - 1 \Longrightarrow верно\ при\ любом\ \ \]
\[y \Longrightarrow ч.т.д.\]