\[\boxed{\mathbf{551\ (551).\ }Еуроки\ - \ ДЗ\ без\ мороки}\]
\[- 3 \leq a \leq 2;\ - 1 \leq b \leq 3\]
\[1) - 9 \leq 3a \leq 6;\ \ \]
\[- 4 \leq 4b \leq 12\]
\[- 13 \leq 3a + 4b \leq 18\ \ \]
\[целых\ значений\ 32.\]
\[2) - 12 \leq 4a \leq 8;\ \ \]
\[- 9 \leq - 3b \leq 3\]
\[- 21 \leq 4a - 3b \leq 11\ \ \]
\[целых\ значений\ 33.\]
\[\boxed{\mathbf{551.\ }Еуроки\ - \ ДЗ\ без\ мороки}\]
\[a_{n} = a_{1} + d(n - 1)\]
\[a_{1} = 17;\ \ \ \ \ d = - 2\]
\[1)\ a_{4} = 17 - 2 \cdot 3 = 17 - 6 = 11\]
\[2)\ a_{15} = 17 - 2 \cdot 14 =\]
\[= 17 - 28 = - 11\]
\[3)\ a_{60} = 17 - 2 \cdot 59 =\]
\[= 17 - 118 = - 101\]