\[y = kx + b;A(3;3);B( - 1;5):\]
\[\left\{ \begin{matrix} 3k + b = 3 \\ - k + b = 5 \\ \end{matrix} \right.\ ( - )\]
\[4k = - 2\]
\[k = - 0,5.\]
\[b = 5 + k = 5 - 0,5 = 4,5.\]
\[Ответ:k = - 0,5;b = 4,5.\]