\[\boxed{\mathbf{466\ (466).}\mathbf{\ }Еуроки\ - \ ДЗ\ без\ мороки}\]
\[5\ \frac{км}{ч = \frac{5 \cdot 1000}{60 \cdot 60} = \frac{5 \cdot 10}{36} =}\]
\[= \frac{25}{18} = 1\frac{7}{18}\ \frac{м}{с}.\]
\[Ответ:83\frac{1}{3}\ \frac{м}{мин;\ \ 1\frac{7}{18}\ \frac{м}{с.}}\]
\[\boxed{\mathbf{466}.}\]
\[1)\ 1,2y + 1,4y = 0,78\]
\[2,6y = 0,78\]
\[y = 0,78\ :2,6\]
\[y = 7,8\ :26\]
\[y = 0,3.\]
\[2)\ 0,5x - 0,3x + 2,73 = 4,49\]
\[0,2x = 4,49 - 2,73\]
\[0,2x = 1,76\]
\[x = 1,76\ :0,2\]
\[x = 17,6\ :2\]
\[x = 8,8.\]