Решебник по алгебре 9 класс Макарычев Задание 919

\[\boxed{\text{919\ (919).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]

\[\textbf{а)}\ \sqrt{98} = \sqrt{49 \cdot 2} = 7\sqrt{2};\]

\[\textbf{б)}\ \sqrt{24} = \sqrt{4 \cdot 6} = 2\sqrt{6};\]

\[\textbf{в)} - \sqrt{242} = - \sqrt{121 \cdot 2} =\]

\[= - 11\sqrt{2};\]

\[\textbf{г)} - \sqrt{75} = - \sqrt{25 \cdot 3} = - 5\sqrt{3};\]

\[\textbf{д)}\ 0,1\sqrt{128} = 0,1\sqrt{64 \cdot 2} =\]

\[= 0,8\sqrt{2};\]

\[\textbf{е)}\ 0,4\sqrt{40} = 0,4 \cdot \sqrt{4 \cdot 10} =\]

\[= 0,8\sqrt{10};\]

\[\textbf{ж)}\ \sqrt{12x^{2}},\ \ x \geq 0,\]

\[\sqrt{12x^{2}} = \sqrt{4x^{2} \cdot 3} = 2x\sqrt{3};\]

\[\textbf{з)}\ \sqrt{18y^{2}},\ \ \ y < 0,\]

\[\sqrt{18y^{2}} = \sqrt{9y^{2} \cdot 2} = - 3y\sqrt{2};\]

\[\textbf{и)}\ \sqrt{5a^{4}} = a²\sqrt{5}.\]