Решебник по математике 6 класс Ерина Никольский рабочая тетрадь Часть 1, 2 Часть 1 | Страница 86

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\[\boxed{\mathbf{7.}}\]

\[\textbf{а)} - \frac{1}{13} + \frac{9}{13} = \frac{8}{13}\]

\[- \frac{11}{12} - \frac{1}{12} = - \frac{12}{12} = - 1\]

\[\textbf{б)} - \frac{3}{14} + \frac{5}{14} = \frac{2}{14} = \frac{1}{7}\]

\[- \frac{13}{14} - \frac{2}{14} = - \frac{15}{14} = - 1\frac{1}{14}\]

\[\textbf{в)} - \frac{5}{21} + \frac{11}{21} = \frac{6}{21} = \frac{2}{7}\]

\[- \frac{16}{17} - \frac{1}{17} = - \frac{17}{17} = - 1\]

\[\boxed{\mathbf{8.}}\]

\[\textbf{а)} - \frac{1}{3} - \frac{1}{6} = - \frac{2}{6} - \frac{1}{6} =\]

\[= - \frac{3}{6} = - \frac{1}{2}\]

\[- \frac{1}{2} + \frac{1}{4} = - \frac{2}{4} + \frac{1}{4} = - \frac{1}{4}\]

\[\frac{1}{16} - \frac{1}{8} = \frac{1}{16} - \frac{2}{16} = - \frac{1}{16}\]

\[\textbf{б)} - \frac{2}{7} - \frac{1}{14} = - \frac{4}{14} - \frac{1}{14} =\]

\[= - \frac{5}{14}\]

\[- \frac{1}{6} + \frac{1}{12} = - \frac{2}{12} + \frac{1}{12} = - \frac{1}{12}\]

\[\frac{1}{32} - \frac{1}{16} = \frac{1}{32} - \frac{2}{32} = - \frac{1}{32}\]

\[\textbf{в)} - \frac{3}{9} - \frac{1}{36} = - \frac{12}{36} - \frac{1}{36} =\]

\[= - \frac{13}{36}\]

\[- \frac{1}{7} + \frac{1}{21} = - \frac{3}{21} + \frac{1}{21} = - \frac{2}{21}\]

\[\frac{1}{128} - \frac{1}{64} = \frac{1}{128} - \frac{2}{128} =\]

\[= - \frac{1}{128}\]

\[\boxed{\mathbf{9.}}\]

\[\textbf{а)} - \frac{2}{36} - \frac{7}{9} = - \frac{2}{36} - \frac{28}{36} =\]

\[= - \frac{30}{36} = - \frac{5}{6}\]

\[- \frac{1}{18} - \frac{5}{6} = - \frac{1}{18} - \frac{15}{18} =\]

\[= - \frac{16}{18} = - \frac{8}{9}\]

\[\frac{3}{7} - \frac{13}{70} = \frac{30}{71} - \frac{13}{70} = \frac{17}{70}\]

\[\textbf{б)} - \frac{7}{72} - \frac{1}{8} = - \frac{7}{72} - \frac{9}{72} =\]

\[= - \frac{16}{72} = - \frac{2}{9}\]

\[- \frac{3}{81} - \frac{5}{9} = - \frac{3}{81} - \frac{45}{81} =\]

\[= - \frac{48}{81} = - \frac{16}{27}\]

\[\frac{2}{9} - \frac{47}{90} = \frac{20}{90} - \frac{47}{90} =\]

\[= - \frac{27}{90} = - \frac{3}{10}\]

\[\textbf{в)} - \frac{5}{54} - \frac{2}{9} = - \frac{5}{54} - \frac{12}{54} = - \frac{17}{54}\]

\[- \frac{5}{14} - \frac{5}{42} = - \frac{15}{42} - \frac{5}{42} =\]

\[= - \frac{20}{42} = - \frac{10}{21}\]

\[\frac{3}{7} - \frac{51}{70} = \frac{30}{70} - \frac{51}{70} = - \frac{21}{70} = - \frac{3}{10}\]

\[\boxed{\mathbf{10.}}\]

\[\textbf{а)}\frac{7}{10} - \frac{2}{15} = \frac{21}{30} - \frac{4}{30} = \frac{17}{30}\]

\[- \frac{3}{10} - \frac{7}{15} = - \frac{9}{30} - \frac{14}{30} = - \frac{23}{30}\]

\[- \frac{7}{15} + \frac{5}{18} = - \frac{42}{90} + \frac{25}{90} = - \frac{17}{90}\]

\[\frac{3}{17} + \frac{2}{35} = \frac{105}{595} + \frac{34}{595} = \frac{139}{595}\]

\[\textbf{б)}\ \frac{9}{24} - \frac{7}{30} = \frac{45}{120} - \frac{28}{120} = \frac{17}{120}\]

\[- \frac{3}{20} - \frac{5}{24} = - \frac{12}{120} - \frac{25}{120} =\]

\[= - \frac{37}{120}\]

\[- \frac{5}{18} + \frac{2}{21} = - \frac{35}{126} + \frac{12}{126} =\]

\[= - \frac{23}{126}\]

\[\frac{3}{11} + \frac{5}{14} = \frac{42}{154} + \frac{55}{154} = \frac{97}{154}\]

\[\textbf{в)}\ \frac{6}{35} - \frac{3}{40} = \frac{48}{280} - \frac{21}{280} = \frac{27}{280}\]

\[- \frac{3}{16} - \frac{5}{18} = - \frac{27}{144} - \frac{40}{144} =\]

\[= - \frac{67}{144}\]

\[- \frac{11}{42} + \frac{3}{56} = - \frac{44}{168} + \frac{9}{168} =\]

\[= - \frac{35}{168} = - \frac{5}{24}\]

\[\frac{2}{15} + \frac{7}{12} = \frac{8}{60} + \frac{35}{60} = \frac{43}{60}\]

\[\boxed{\mathbf{11.}}\]

\[\textbf{а)}\ \frac{6}{7} + \left( - \frac{9}{7} \right) = - \frac{2}{7}\]

\[- \frac{5}{11} + \left( - \frac{6}{11} \right) = - \frac{11}{11} = - 1\]

\[- \frac{3}{7} + \frac{4}{7} = \frac{1}{7}\]

\[\textbf{б)}\ \frac{7}{8} + \left( - \frac{20}{8} \right) = - \frac{13}{8} = - 1\frac{5}{8}\]

\[- \frac{7}{13} + \left( - \frac{6}{13} \right) = - \frac{13}{13} = - 1\]

\[- \frac{5}{9} + \frac{6}{9} = \frac{1}{9}\]

\[\textbf{в)}\ \frac{3}{11} + \left( - \frac{9}{11} \right) = - \frac{6}{11}\]

\[- \frac{11}{25} + \frac{4}{25} = - \frac{7}{25}\]

\[- \frac{8}{13} + \frac{11}{13} = \frac{3}{13}\]