\[\boxed{\text{492}\text{\ (492)}\text{.}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[|a| = a\ \ \ \ \ \ и\ \ \ \ \ \ \ |a| = - a\text{\ \ \ \ }\]
\[выполняется\ для\ нуля.\]
\[\boxed{\text{4}\text{9}\text{2}\text{.}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[1)\ \frac{4}{5} = \frac{8}{10} = 0,8;\]
\[2)\ \frac{3}{8} = \frac{375}{1000} = 0,375;\]
\[3)\ \frac{7}{16} = \frac{4375}{10000} = 0,4375;\]
\[4)\ \frac{97}{80} = 1\frac{17}{80} = 1\frac{2125}{10000} =\]
\[= 1,2125;\]
\[5)\ \frac{42}{15} = 2,8.\ \]