\[\boxed{\text{558\ (558).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[\textbf{а)}\ \left\{ \begin{matrix} y = 7x - 1 \\ y = 2x\ \ \ \ \ \ \ \ \\ \end{matrix} \right.\ \] \[2x = 7x - 1\] \[5x = 1\] \[x = \frac{1}{5} = 0,2;\] \[y = 2 \cdot 0,2 = 0,4.\] \[Ответ:(0,2;0,4)\] |
\[\textbf{б)}\ \left\{ \begin{matrix} y = 3x - 11 \\ y = 4\ \ \ \ \ \ \ \ \ \ \ \ \\ \end{matrix} \right.\ \] \[3x - 11 = 4\] \[3x = 15\] \[x = \frac{15}{3} = 5;\] \[y = 4.\] \[Ответ:(5;4).\] |
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\[\textbf{в)}\ \left\{ \begin{matrix} y = 5x + 8 \\ y = 3x + 2 \\ \end{matrix} \right.\ \] \[5x + 8 = 3x + 2\] \[2x = - 6\] \[x = - 3;\] \[y = 3 \cdot ( - 3) + 2 = - 9 + 2 = - 7.\] \[Ответ:( - 3;\ - 7)\] |
\[\textbf{г)}\ \left\{ \begin{matrix} y = 4 - x \\ y = 3x\ \ \ \ \ \\ \end{matrix} \right.\ \] \[4 - x = 3x\] \[4x = 4\] \[x = 1;\] \[y = 3 \cdot 1 = 3.\] \[Ответ:(1;3)\text{.\ }\] |