\[\boxed{\ \mathbf{980\ (980)}.\ Еуроки\ - \ ДЗ\ без\ мороки}\]
\[1)\ y \cdot 4,9 = 2,94\]
\[y = 2,94\ :4,9\]
\[y = 0,6\]
\[Ответ:0,6.\]
\[2)\ y \cdot 0,7 = 0,0091\]
\[y = 0,0091\ :0,7\]
\[y = 0,013\]
\[Ответ:0,013.\]
\[3)\ y\ :2,3 = 5,6\]
\[y = 5,6 \cdot 2,3\]
\[y = 12,88\]
\[Ответ:12,88.\]
\[4)\ 7,8a + 5,4a = 3,3\]
\[13,2a = 3,3\]
\[a = 3,3\ :13,2\]
\[a = 0,25\]
\[Ответ:0,25.\]
\[5)\ 1,3x - 0,82x = 6\]
\[0,48x = 6\]
\[x = 6\ :0,48\]
\[x = 12,5\]
\[Ответ:12,5.\ \]
\[6)\ x - 0,28x = 36\]
\[0,72x = 36\]
\[x = 36\ :0,72\]
\[x = 50\]
\[Ответ:50.\]