Решебник по алгебре 9 класс Мерзляк Задание 949

\[\boxed{\mathbf{949\ (949).\ }Еуроки\ - \ ДЗ\ без\ мороки}\]

\[1)\left\{ \begin{matrix} x - 3 < 2x - 3 \\ 4x + 5 > 10 - x \\ \end{matrix} \right.\ \text{\ \ \ \ \ \ }\left\{ \begin{matrix} - x < 0 \\ 5x > 5 \\ \end{matrix} \right.\ \text{\ \ \ \ \ }\]

\[\left\{ \begin{matrix} x > 0 \\ x > 1 \\ \end{matrix} \right.\ ,\ \ x > 1\]

\[Ответ:(1;\ + \infty).\]

\[2)\ \left\{ \begin{matrix} 9 + 2x \leq 3x + 7 \\ x - 2 > 2x - 5 \\ \end{matrix} \right.\ \text{\ \ \ \ \ \ }\]

\[\ \left\{ \begin{matrix} - x \leq - 2 \\ - x > - 3 \\ \end{matrix} \right.\ \text{\ \ \ \ \ \ \ }\left\{ \begin{matrix} x \geq 2 \\ x < 3 \\ \end{matrix} \right.\ \]

\[Ответ:\lbrack 2;3).\]

\[3)\ (x - 5)^{2} - 15 \geq\]

\[\geq (x - 3)(x - 4) - 50\ \ \ \ \ и\ \ \ \ \]

\[\ 4 \cdot (x + 7) - 16 \geq 2 - x\]

\[x^{2} - 10x + 25 - 15 \geq x^{2} -\]

\[- 7x + 12 - 50\ \ \ \text{\ \ \ }\]

\[\ \ 4x + 28 - 16 \geq 2 - x\]

\[- 3x \geq - 48,\ \ x \leq 16\ \ \ \ \ \]

\[\ 5x \geq - 10,\ \ x \geq - 2\]

\[Ответ:\lbrack - 2;16\rbrack.\]

\[4)\ \left\{ \begin{matrix} \frac{x - 1}{4} + \frac{x + 1,7}{3} \geq \frac{3x + 1}{5}\ \ \ | \cdot 60 \\ \frac{x + 2}{4} - \frac{x + 8}{5} < \frac{3x - 1}{10}\ \ \ \ \ \ | \cdot 20 \\ \end{matrix} \right.\ \ \]

\[\left\{ \begin{matrix} 15x - 15 + 20x + 34 \geq 36x + 12 \\ 5x + 10 - 4x - 32 < 6x - 2\ \ \ \ \ \ \ \ \ \\ \end{matrix} \right.\ \]

\[\left\{ \begin{matrix} - x \geq - 7 \\ - 5x < 20 \\ \end{matrix} \right.\ \text{\ \ \ \ \ \ \ \ \ }\left\{ \begin{matrix} x \leq 7 \\ x > - 4 \\ \end{matrix} \right.\ \]

\[Ответ:( - 4;7\rbrack\text{.\ }\]