\[y = kx + b;\ \ \ A(2;1);\ \ B( - 4;10).\]
\[Подставим\ координаты\ точек\ в\ \]
\[уравнение\ прямой\ и\ запишем\]
\[систему:\]
\[\left\{ \begin{matrix}
2k + b = 1\ \ \ \ \ \\
- 4k + b = 10 \\
\end{matrix} \right.\ ( - )\]
\[6k = - 9\]
\[k = - 1,5.\]
\[\left\{ \begin{matrix}
b = 1 - 2k \\
k = - 1,5\ \ \ \ \\
\end{matrix} \right.\ \text{\ \ \ \ \ \ \ \ }\left\{ \begin{matrix}
b = 1 + 3 \\
k = - 1,5\ \\
\end{matrix} \right.\ \text{\ \ \ \ \ \ }\left\{ \begin{matrix}
b = 4\ \ \ \ \ \ \ \\
k = - 1,5 \\
\end{matrix} \right.\ \]
\[Уравнение\ прямой:\]
\[y = - 1,5x + 4.\]