ГДЗ по алгебре 9 класс Макарычев Задание 308

\[\boxed{\text{308\ (308).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]

\[\textbf{а)}\ x^{2} < 16\]

\[x^{2} - 16 < 0\]

\[(x - 4)(x + 4) < 0\]

\[x \in ( - 4;4).\]

\[\textbf{б)}\ x^{2} \geq 3\]

\[x^{2} - 3 \geq 0\]

\[\left( x - \sqrt{3} \right)\left( x + \sqrt{3} \right) \geq 0\]

\[x \in \left( - \infty;\ - \sqrt{3} \right\rbrack \cup \left\lbrack \sqrt{3}; + \infty \right).\]

\[\textbf{в)}\ 0,2x^{2} > 1,8\]

\[0,2x^{2} - 1,8 > 0\ \ \ \ \ \ \ |\ :0,2\]

\[x^{2} - 9 > 0\]

\[(x - 3)(x + 3) > 0\]

\[x \in ( - \infty;\ - 3) \cup (3;\ + \infty).\]

\[\textbf{г)} - 5x^{2} \leq x\]

\[5x^{2} + x \geq 0\]

\[5x(x + 0,2) \geq 0\]

\[x \in ( - \infty; - 0,2\rbrack \cup \lbrack 0; + \infty).\]

\[\textbf{д)}\ 3x^{2} < - 2x\]

\[3x^{2} + 2x < 0\]

\[3x\left( x + \frac{2}{3} \right) < 0\]

\[x \in \left( - \frac{2}{3};0 \right).\]

\[\textbf{е)}\ 7x < x^{2}\]

\[x^{2} - 7x > 0\]

\[x(x - 7) > 0\]

\[x \in ( - \infty;0) \cup (7; + \infty).\]