\[Страница\ 55.\]
\[11.\ Действия\ сложения\ и\ \]
\[вычитания\ смешанных\ чисел\]
\[\boxed{\mathbf{1.}}\]
\[\textbf{а)}\ 6\frac{2}{7} + 1 = 7 + \frac{2}{7} = 7\frac{2}{7}\]
\[\textbf{б)}\ 6\frac{2}{7} - 1 = 5 + \frac{2}{7} = 5\frac{2}{7}\]
\[\textbf{в)}\ 5 + \frac{1}{3} = 5\frac{1}{3}\]
\[\textbf{г)}\ 5 - \frac{1}{3} = 4\frac{3}{3} - \frac{1}{3} = 4 + \frac{2}{3} = 4\frac{2}{3}\]
\[\textbf{д)}\ 7\frac{8}{5} + 3\frac{1}{8} = 10 + \left( \frac{5}{8} + \frac{1}{8} \right) =\]
\[= 10 + \frac{6}{8} = 10\frac{3}{4}\]
\[\textbf{е)}\ 5\frac{3}{10} + 2\frac{1}{5} = 5\frac{3}{10} + 2\frac{2}{10} =\]
\[= 7 + \left( \frac{3}{10} + \frac{2}{10} \right) = 7 + \frac{5}{10} = 7\frac{1}{2}\]
\[\textbf{ж)}\ 5\frac{3}{10} - 2\frac{1}{5} = 5\frac{3}{10} - 2\frac{2}{10} =\]
\[= 3 + \left( \frac{3}{10} - \frac{2}{10} \right) = 3 + \frac{1}{10} =\]
\[= 3\frac{1}{10}\]
\[\textbf{з)}\ 3\frac{1}{2} - 1\frac{3}{4} = 3\frac{2}{4} - 1\frac{3}{4} =\]
\[= 2\frac{6}{4} - 1\frac{3}{4} = 1 + \frac{3}{4} = 1\frac{3}{4}\]