\[Страница\ 107.\]
\[\boxed{\mathbf{7.}}\]
\[\textbf{а)}\ 1\ м = 1000\ мм;\]
\[1000\ :1\]
\[\textbf{б)}\ 1\ га = 10\ 000\ м^{2};\ \]
\[10\ 000\ :1\]
\[\textbf{в)}\ 1\ р. = 100\ к.;\]
\[100\ :35 = 20\ :7\]
\[\textbf{г)}\ 1\ ч = 60\ мин;\]
\[60\ :25 = 12\ :5\]
\[\textbf{д)}\ 1\ дм^{2} = 100\ см^{2};\]
\[560\ :0,7 = 5600\ :7 = 800\ :1\]
\[\textbf{е)}\ 1\ дм^{2} = 100\ см^{2};\ \]
\[0,7\ :560 = 7\ :5600 = 1\ :800\]
\[\textbf{ж)}\ 1\ дм = 100\ мм;\]
\[570\ :1,9 = 5700\ :19 = 300\ :1\]
\[\textbf{з)}\ 1\ м^{2} = 10\ 000\ см^{2};\]
\[8000\ :2 = 4000\ :1\]
\[\textbf{и)}\ 1\ км^{2} = 100\ га;\]
\[10\ :100 = 1\ :10\]
\[к)\ 1м^{2} = 10\ 000\ см^{2};\]
\[9\ 000\ :40 = 900\ :4 = 225\ :1\]
\[\boxed{\mathbf{8.}}\]
\[\frac{a}{b} = \frac{5}{6};\]
\[\frac{b}{a} = \frac{6}{5} = 1,2.\]
\[\boxed{\mathbf{9.}}\]
\[\frac{x}{y} = 3\frac{2}{7} = \frac{23}{7}\]
\[\frac{y}{x} = \frac{7}{23}.\]
\[\boxed{\mathbf{10.}}\]
\[\textbf{а)}\ 16,4\ :0,4 = 41 + 9 =\]
\[= 50 \cdot 0,8 = 40\]
\[\textbf{б)}\ 8,5\ :1,7 = 5 \cdot 0,5 =\]
\[= 2,5 + 17,5 = 20\]
\[\textbf{в)}\ 0,4 \cdot 0,96 = 0,384\ :8 =\]
\[= 0,048 + 0,052 = 0,1\]
\[\textbf{г)}\ 2,5 \cdot 11 = 27,5 - 4,5 =\]
\[= 23\ :2,3 = 10 \cdot 4,9 =\]
\[= 49 + 11 = 60\]
\[\textbf{д)}\ 1,5 \cdot 7 = 10,5\ :0,3 = 35 \cdot 5 =\]
\[= 175 + 0,4 = 175,4 - 75,4 =\]
\[= 100\]