\[\boxed{\mathbf{1010\ (1010)}.\ Еуроки\ - \ ДЗ\ без\ мороки}\]
\[1)\ 34,2 + 1,6 = 35,8\ \left( \frac{км}{ч} \right) -\]
\[скорость\ лодки\ по\ течению.\]
\[2)\ 28,64\ :35,8 = 0,8\ (ч) -\]
\[время\ по\ течению.\]
\[3)\ 34,2 - 1,6 = 32,6\ \left( \frac{км}{ч} \right) -\]
\[скорость\ против\ течения.\]
\[4)\ 52,16\ :32,6 = 1,6\ (ч) -\]
\[время\ лодки\ против\ течения.\]
\[5)\ 0,8 + 1,6 = 2,4\ (ч) - плыла\ \]
\[лодка.\]
\[Ответ:2,4\ часа.\]
\[\boxed{\mathbf{1010}\mathbf{.}\mathbf{\ }}\]
\[1)\ \frac{1^{\backslash 5}}{4} + \frac{3^{\backslash 4}}{5} = \frac{5 + 12}{20} = \frac{17}{20}\]
\[2)\ \frac{13^{\backslash 2}}{16} - \frac{9}{32} = \frac{26 - 9}{32} = \frac{17}{32}\]
\[3)\ \frac{14^{\backslash 2}}{15} - \frac{7^{\backslash 3}}{10} = \frac{28 - 21}{30} = \frac{7}{30}\]
\[4)\ \frac{3^{\backslash 3}}{8} + \frac{1^{\backslash 4}}{6} = \frac{9 + 4}{24} = \frac{13}{24}\]
\[5)\ \frac{9^{\backslash 4}}{25} - \frac{7^{\backslash 5}}{20} = \frac{36 - 35}{100} = \frac{1}{100}\]
\[6)\ \frac{11^{\backslash 2}}{24} - \frac{3^{\backslash 3}}{16} = \frac{22 - 9}{48} = \frac{13}{48}\]
\[7)\ \frac{1^{\backslash 4}}{3} - \frac{1^{\backslash 2}}{6} + \frac{1^{\backslash 3}}{4} =\]
\[= \frac{4 - 2 + 3}{12} = \frac{5}{12}\]
\[8)\ \frac{2^{\backslash 9}}{5} + \frac{4^{\backslash 3}}{15} - \frac{5^{\backslash 5}}{9} =\]
\[= \frac{18 + 12 - 25}{45} = \frac{5}{45} = \frac{1}{9}\]