Решебник по алгебре 9 класс Макарычев Задание 760

\[\boxed{\text{760\ (760).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]

\[\textbf{а)}\ A_{6}^{2} = \frac{6!}{4!} = 5 \cdot 6 = 30.\]

\[\textbf{б)}\ A_{6}^{4} = \frac{6!}{2!} = 3 \cdot 4 \cdot 5 \cdot 6 = 360.\]

\[\textbf{в)}\ P_{6} = 6! = 720.\]

\[\boxed{\text{760.}\text{\ }\text{ОК\ ГДЗ\ -\ домашка\ на\ 5}}\]

\[y = kx + b \Longrightarrow уравнение\ \]

\[прямой.\]

\[\textbf{а)}\ x_{1} = 0,\ \ y_{1} = 30,\]

\[x_{2} = 6,\ \ y_{2} = 0,\]

\[\left\{ \begin{matrix} 30 = b\ \ \ \ \ \ \\ 0 = 6k + b \\ \end{matrix} \right.\ \Longrightarrow \left\{ \begin{matrix} b = 30 \\ k = - 5 \\ \end{matrix} \right.\ \Longrightarrow\]

\[\Longrightarrow y = - 5x + 30.\]

\[\textbf{б)}\ x_{1} = 2,\ \ y_{1} = 3,\]

\[x_{2} = - 2,\ \ y_{2} = 10,\]

\[\left\{ \begin{matrix} 3 = 2k + b\ \ \ \\ 10 = - 2k + b \\ \end{matrix} \right.\ \Longrightarrow\]

\[\Longrightarrow \left\{ \begin{matrix} 2b = 10 + 3 \\ 3 = 2k + b\ \ \ \\ \end{matrix} \right.\ \Longrightarrow\]

\[\Longrightarrow \left\{ \begin{matrix} b = 6,5\ \ \ \ \ \\ 2k = - 3,5 \\ \end{matrix} \right.\ \]

\[\Longrightarrow \left\{ \begin{matrix} b = 6,5\ \ \ \ \ \\ k = - 1,75 \\ \end{matrix} \right.\ \Longrightarrow\]

\[\Longrightarrow y = - 1,75x + 6,5 \Longrightarrow\]

\[\Longrightarrow 4y + 7x = 26.\]