\[\boxed{\text{479}\text{\ (479)}\text{.}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[1)\ \frac{1}{6} < 0,2 = \frac{1}{5}\text{\ \ }\]
\[2)\ \frac{7}{9} = 0,(7) > 0,77\ \ \]
\[3) - 1,(645) < - 1,(643)\text{.\ }\]
\[\boxed{\text{4}\text{79}\text{.}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[1)\ f(x) = \frac{4}{x - 5}\]
\[x - 5 \neq 0\]
\[x \neq 5.\]
\[D(y) = ( - \infty;5) \cup (5; + \infty).\]
\[2)\ f(x) = \frac{x + 1}{x^{2} + 3x}\]
\[x^{2} + 3x = 0\]
\[x(x + 3) = 0\]
\[x \neq 0;\ \ x \neq - 3.\]
\[D(y) = ( - \infty; - 3) \cup ( - 3;0) \cup (0; + \infty).\]