\[\boxed{\begin{matrix} \text{Проверочная\ работа\ №}\text{2.\ Сложение\ и\ вычитание\ дробей\ с\ } \\ \text{\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ одинаковыми\ знаменателями} \\ \end{matrix}}\]
\[\boxed{\text{1.}}\]
\[\textbf{а)}\ \frac{3}{14} + \frac{7}{14} = \frac{3 + 7}{14} = \frac{10}{14}\]
\[\textbf{б)}\ \frac{8}{15} + \frac{7}{15} = \frac{8 + 7}{15} = \frac{15}{15} = 1\]
\[\textbf{в)}\ \frac{7}{14} - \frac{3}{14} = \frac{7 - 3}{14} = \frac{4}{14}\]
\[\textbf{г)}\ \frac{8}{15} - \frac{7}{15} = \frac{8 - 7}{15} = \frac{1}{15}\]
\[\textbf{д)}\ \frac{6}{21} + \frac{10}{21} - \frac{13}{21} =\]
\[= \frac{6 + 10 - 13}{21} = \frac{3}{21}\]
\[\textbf{е)}\ \frac{35}{48} - \frac{20}{48} + \frac{1}{48} =\]
\[= \frac{35 - 20 + 1}{48} = \frac{16}{48}\]
\[\boxed{\text{2.}}\]
\[\textbf{а)}\ \frac{13}{56} + y = \frac{34}{56}\]
\[y = \frac{34}{56} - \frac{13}{56}\]
\[y = \frac{21}{56}.\]
\[\textbf{б)}\ x - \frac{7}{90} = \frac{39}{90}\]
\[x = \frac{39}{90} + \frac{7}{90}\]
\[x = \frac{46}{90}.\]
\[\textbf{в)}\ \frac{27}{48} + \frac{15}{48} - a = \frac{17}{48}\]
\[\frac{42}{48} - a = \frac{17}{48}\]
\[a = \frac{42}{48} - \frac{17}{48}\]
\[a = \frac{25}{48}.\]
\[\textbf{г)}\ b + \frac{14}{23} - \frac{3}{23} = \frac{20}{23}\]
\[b + \frac{11}{23} = \frac{20}{23}\]
\[b = \frac{20}{23} - \frac{11}{23}\]
\[b = \frac{9}{23}\text{.\ }\]
\[\boxed{\text{3.}}\]
\[\textbf{а)}\ \frac{6}{5} > 1;\ \frac{1}{2} < 1:\]
\[\frac{1}{2} < \frac{6}{5};\]
\[верно.\]
\[\textbf{б)}\ верно;\]
\[\textbf{в)}\ верно.\]
\[Ответ:все\ утверждения\ верны.\]
Глава 30. Деление натуральных чисел и дроби