\[Страница\ 50.\]
\[\boxed{\mathbf{7.}}\]
\[\textbf{а)}\ 1 + \frac{1}{5} = 1\frac{1}{5}\]
\[\textbf{б)}\frac{7}{15} - 0,4 = \frac{7}{15} - \frac{2^{\backslash 3}}{5} =\]
\[= \frac{7}{15} - \frac{6}{15} = \frac{1}{15}\]
\[\textbf{в)}\ 0,75 + \frac{1}{4} = \frac{3}{4} + \frac{1}{4} = \frac{4}{4} = 1\]
\[\textbf{г)}\ 0,85 - \frac{5}{16} = \frac{17^{\backslash 4}}{20} - \frac{5^{\backslash 5}}{16} =\]
\[= \frac{68}{80} - \frac{25}{80} = \frac{43}{80}\]
\[\textbf{д)}\frac{1}{2} - 0,5 = \frac{1}{2} - \frac{1}{2} = 0\]
\[\textbf{е)}\frac{3}{4} - 0,125 = \frac{3^{\backslash 2}}{4} - \frac{1}{8} =\]
\[= \frac{6}{8} - \frac{1}{8} = \frac{5}{8}\]
\[\textbf{ж)}\ \frac{7}{36} + 0,25 = \frac{7}{36} + \frac{1^{\backslash 9}}{4} =\]
\[= \frac{7}{36} + \frac{9}{36} = \frac{16}{36} = \frac{4}{9}\]
\[\textbf{з)}\frac{1}{100} + 0,7 = \frac{1}{100} + \frac{7^{\backslash 10}}{10} =\]
\[= \frac{1}{100} + \frac{70}{100} = \frac{71}{100}\ \]
\[\boxed{\mathbf{8.}}\]
\[\textbf{а)}\ 4,17 + \frac{9}{20} = 4,17 + \frac{45}{100} =\]
\[= 4,17 + 0,45 = 4,62\]
\[\textbf{б)}\ \frac{3}{4} - 0,29 = 0,75 - 0,29 =\]
\[= 0,46\]
\[\textbf{в)}\ \frac{1}{4} + \frac{9}{50} = \frac{25}{100} + \frac{18}{100} =\]
\[= 0,25 + 0,18 = 0,43\]
\[\textbf{г)}\ \frac{3}{5} - \frac{1}{2} = 0,6 - 0,5 = 0,1\]
\[\textbf{д)}\ \frac{17}{20} - 0,27 = \frac{85}{100} - 0,27 =\]
\[= 0,85 - 0,27 = 0,53\]
\[\textbf{е)}\ \frac{1}{8} + 0,875 = \frac{125}{1000} + 0,875 =\]
\[= 0,125 + 0,875 = 1\]
\[\textbf{ж)}\ \frac{1}{5} - 0,09 = 0,2 - 0,09 = 0,11\]
\[\textbf{з)}\ \frac{7}{25} + 2,15 = \frac{28}{100} + 2,15 =\]
\[= 0,28 + 2,15 = 2,43\]
\[\boxed{\mathbf{9.}}\]
\[\textbf{а)}\ x = \frac{17^{\backslash 4}}{20} - \frac{3^{\backslash 5}}{16}\]
\[x = \frac{68}{80} - \frac{15}{80} = \frac{53}{80}\]
\[Ответ:\frac{53}{80}\text{.\ }\]
\[\textbf{б)}\ y = \frac{7^{\backslash 5}}{12} - \frac{8^{\backslash 4}}{15}\]
\[y = \frac{35}{60} - \frac{32}{60} = \frac{3}{60}\]
\[y = \frac{1}{20}\]
\[Ответ:\frac{1}{20}.\]
\[\textbf{в)}\ a = \frac{7^{\backslash 2}}{30} + \frac{1^{\backslash 5}}{12}\]
\[a = \frac{14}{60} + \frac{5}{60} = \frac{19}{60}\]
\[Ответ:\ \frac{19}{60}.\]
\[\textbf{г)}\ b = \frac{25^{\backslash 2}}{39} - \frac{15^{\backslash 3}}{26}\]
\[b = \frac{50}{78} - \frac{45}{78} = \frac{5}{78}\]
\[Ответ:\frac{5}{78}.\]