\[\boxed{Страница\ 77.}\]
\[\boxed{\mathbf{5.}}\]
\[2\ а = 200\ м^{2}\]
\[8\ га\ 3\ а = 803\ а = 80\ 300\ м^{2}\]
\[6\ соток = 600\ а = 60\ 000\ м^{2}\]
\[5\ га\ 4\ а = 504\ а\]
\[9000\ а = 90\ га\]
\[32\ м^{2} = \frac{32}{10000}\ га\]
\[48\ 000\ м^{2} = 480\ а = 4\ га\ 80\ а\]
\[\boxed{\mathbf{6.}}\]
\[15\ а\ 8\ м^{2} - 9\ а\ 52\ м^{2} =\]
\[= 14\ а\ 108\ м^{2} - 9\ а\ 52\ м^{2} =\]
\[= 5\ а\ 56\ м^{2}\]
\[4\ га\ 9\ а\ 27\ м^{2} + 6\ га\ 73\ м^{2} =\]
\[= 10\ га\ 9\ а\ 100\ м^{2} = 10\ га\ 10\ а\]
\[38\ а\ 4\ м^{2} \cdot 25 = 950\ а\ 100\ м^{2} =\]
\[= 951\ а = 9\ га\ 51\ а\]
\[5\ га\ 64\ а\ :8 = 56\ 400\ м^{2}\ :8 =\]
\[= 7050\ м^{2} = 70\ а\ 50\ м^{2}\]
\[\boxed{\mathbf{7.}}\]
\[\textbf{а)}\ m + 5\frac{4}{7}\ при\ m = \frac{3}{7};\ \ \ 2\frac{1}{7};\ \ \]
\[3\frac{6}{7}:\]
\[\frac{3}{7} + 5\frac{4}{7} = 5\frac{7}{7} = 6;\]
\[2\frac{1}{7} + 5\frac{4}{7} = 7\frac{5}{7};\]
\[3\frac{6}{7} + 5\frac{4}{7} = 8\frac{10}{7} = 9\frac{3}{7}.\]
\[\textbf{б)}\ k - 4\frac{3}{12}\ при\ k = 5;\ \ 7\frac{8}{12};\ \ \]
\[\ 9\frac{1}{12}:\]
\[5 - 4\frac{3}{12} = 4\frac{12}{12} - 4\frac{3}{12} = \frac{9}{12};\]
\[7\frac{8}{12} - 4\frac{3}{12} = 3\frac{5}{12};\]
\[9\frac{1}{12} - 4\frac{3}{12} = 8\frac{13}{12} - 4\frac{3}{12} =\]
\[= 4\frac{10}{12}.\]
\[\boxed{\mathbf{8.}}\]
\[1\ ковш - это\ 6\ чашек.\]
\[2 \cdot 6 \cdot 2 = 24\ (чашки) - воды\ в\ \]
\[целом\ ведерке.\]
\[Ответ:24\ чашки.\]