\[\boxed{\mathbf{Страница}\mathbf{\ 14}\mathbf{.}\mathbf{\ }\mathbf{Еуроки}\mathbf{\ - \ }\mathbf{ДЗ}\mathbf{\ }\mathbf{без}\mathbf{\ }\mathbf{мороки}}\]
\[\boxed{\mathbf{10.}}\]
\[5:\]
\[(5 + 9) \cdot 100 = 14 \cdot 100 = 1400;\ \ \]
\[16:\]
\[(16 + 9) \cdot 100 = 25 \cdot 100 =\]
\[= 2500;\ \ \]
\[20:\]
\[(20 + 9) \cdot 100 = 29 \cdot 100 =\]
\[= 2900;\ \ \]
\[49:\]
\[(49 + 9) \cdot 100 = 58 \cdot 100 =\]
\[= 5800.\]
\[\boxed{\mathbf{11.}}\]
\[1)\ 36\ :(36 - 27)\]
\[2)\ 48 - 48\ :3\]
\[\boxed{\mathbf{12.}}\]
\[1)\ 28\ :4 = 7\ (см) - сторона\ \]
\[квадрата.\]
\[2)\ 7 + 2 = 9\ (см) - новая\ \]
\[сторона.\]
\[3)\ 9 \cdot 9 = 81\ \left( см^{2} \right) - площадь\ \]
\[нового\ квадрата.\]
\[Ответ:81\ см^{2}.\]