\[\boxed{\text{1204\ (1204).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[n(n + 2)(n + 4)(n + 6) + 16 =\]
\[= \left( n^{2} + 6n \right)\left( n^{2} + 6n + 8 \right) + 16 =\]
\[= \left( n^{2} + 6n + 4 \right)^{2} - 4^{2} + 16 =\]
\[= \left( n^{2} + 6n + 4 \right)^{2}\ \]
\[\boxed{\text{1204.\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[6y = 5x - 3\ \]
\[y = \frac{5x - 3}{6}\text{\ \ }\]
\[y = \frac{5}{6}x - \frac{1}{2}\]
\[при\ x = 3:\ \ \]
\[y = \frac{15 - 3}{6}\ \]
\[y = 2 \Longrightarrow \ \ (3;2)\]
\[Ответ:1\ пара;\ \ \ (3;2).\]