\[\boxed{\mathbf{778}\mathbf{.}}\]
\[1)\ s(t) = 2t + 1:\]
\[\frac{f(t + h) - f(t)}{h} =\]
\[= \frac{2(t + h) + 1 - 2t - 1}{h} =\]
\[= \frac{2t + 2h - 2t}{h} = \frac{2h}{h} = 2\]
\[v = \lim_{h \rightarrow 0}2 = 2.\]
\[Ответ:\ \ 2.\]
\[2)\ s(t) = 2 - 3t:\]
\[\frac{f(t + h) - f(t)}{h} =\]
\[= \frac{2 - 3(t + h) - 2 + 3t}{h} =\]
\[= \frac{- 3t - 3h + 3h}{h} = - \frac{3h}{h} = - 3\]
\[v = \lim_{h \rightarrow 0}( - 3) = - 3.\]
\[Ответ:\ - 3.\]