Решебник по математике 5 класс Виленкин Часть 1, 2 Часть 2. Параграф 5. Обыкновенные дроби Задание 418

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\[1)\ а)\ \left( \frac{9}{16} + \frac{1}{4} \right) - \frac{1}{16} =\]

\[= \left( \frac{9}{16} - \frac{1}{16} \right) + \frac{1}{4} = \frac{8}{16} + \frac{1}{4} =\]

\[= \frac{2}{4} + \frac{1}{4} = \frac{3}{4}\ \]

\[\textbf{б)}\ \left( \frac{1}{9} + \frac{7}{18} \right) - \frac{5}{18} =\]

\[= \frac{1}{9} + \left( \frac{7}{18} - \frac{5}{18} \right) = \frac{1}{9} + \frac{2}{18} =\]

\[= \frac{1}{9} + \frac{1}{9} = \frac{2}{9}\ \]

\[2)\ а)\ \frac{13}{14} - \left( \frac{3}{14} + \frac{1}{2} \right) =\]

\[= \left( \frac{13}{14} - \frac{3}{14} \right) - \frac{1}{2} = \frac{10}{14} - \frac{1}{2} =\]

\[= \frac{10}{14} - \frac{7}{14} = \frac{3}{14}\ \]

\[\textbf{б)}\ \frac{13}{21} - \left( \frac{1}{3} + \frac{4}{21} \right) =\]

\[= \left( \frac{13}{21} - \frac{4}{21} \right) - \frac{1}{3} = \frac{9}{21} - \frac{1}{3} =\]

\[= \frac{9}{21} - \frac{7}{21} = \frac{2}{21}\text{\ \ }\]