\[\boxed{\mathbf{979.ОК\ ГДЗ - домашка\ на}\ 5}\]
\[\mathbf{Дано:}\]
\[A( - 8;6);\]
\[B( - 3; - 1);\]
\[M(5;y);\]
\[M \in AB.\]
\[\mathbf{Найти:}\]
\[\mathbf{Решение.}\]
\[1) - \left\{ \begin{matrix} - 6 - 8k + b \\ - 1 = - 3k + b \\ \end{matrix} \right.\ \Longrightarrow - 5 =\]
\[= - 5k \Longrightarrow k = 1;\]
\[\left\{ \begin{matrix} k = 1 \\ b = 2 \\ \end{matrix} \right.\ .\]
\[2)\ y = x + 2\]
\[y = 5 + 2 = 7\]
\[M(5;7).\]
\[Ответ:\ y = 7.\]