\[\boxed{\text{175\ (175).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[\textbf{а)}\ \sqrt[3]{7} \approx 1,9;\]
\[\textbf{б)}\ \sqrt[3]{20} \approx 2,7;\]
\[\textbf{в)}\ \sqrt[4]{30} \approx 2,3;\]
\[\textbf{г)}\ \sqrt[5]{- 48} \approx - 2,2.\]
\[\boxed{\text{175.}\text{\ }\text{ОК\ ГДЗ\ -\ домашка\ на\ 5}}\]
\[y = \frac{8x - 7}{x} = 8 - \frac{7}{x}\]
\[\frac{7}{x}\ \ должно\ быть\ целым \Longrightarrow\]
\[\Longrightarrow \left\{ \begin{matrix} \frac{7}{x} = 7\ \ \\ \frac{7}{x} = 1\ \ \ \\ \frac{7}{x} = - 1 \\ \frac{7}{x} = - 7 \\ \end{matrix} \right.\ \Longrightarrow \left\{ \begin{matrix} x = 1\ \ \\ x = 7\ \ \ \\ x = - 7 \\ x = - 1 \\ \end{matrix} \right.\ \]
\[y(1) = 8 - \frac{7}{1} = 1;\]
\[y(7) = 8 - \frac{7}{7} = 8 - 1 = 7;\]
\[y( - 7) = 8 + \frac{7}{7} = 8 + 1 = 9;\]
\[y( - 1) = 8 + \frac{7}{1} = 8 + 7 = 15;\]
\[Ответ:(1;1),\ (7;7),\ ( - 7;9),\ \]
\[( - 1;15).\]