\[\boxed{\mathbf{536\ (536)}.\ Еуроки\ - \ ДЗ\ без\ мороки}\]
\[1)\ (53 + a)\ :7\ \]
\[при\ \ a = 3:\]
\[(53 + 3)\ :7 = 56\ :7 = 8.\]
\[2)\ (a + 24)\ :5 = x\ (ост.\ 2)\ \]
\[\ при\ \ a = 3:\]
\[(3 + 24)\ :5 = 27\ :5 =\]
\[= 5\ (ост.\ 2).\]