Решение:
- а) \(2\frac{1}{2} + 1\frac{1}{3}\)
\(2\frac{1}{2} + 1\frac{1}{3} = \frac{5}{2} + \frac{4}{3} = \frac{15}{6} + \frac{8}{6} = \frac{23}{6} = 3\frac{5}{6}\) - б) \(4 - 2\frac{4}{7}\)
\(4 - 2\frac{4}{7} = 4 - \frac{18}{7} = \frac{28}{7} - \frac{18}{7} = \frac{10}{7} = 1\frac{3}{7}\) - в) \(2,5 + 1\frac{2}{3} - 3\frac{1}{6}\)
\(2,5 + 1\frac{2}{3} - 3\frac{1}{6} = \frac{5}{2} + \frac{5}{3} - \frac{19}{6} = \frac{15}{6} + \frac{10}{6} - \frac{19}{6} = \frac{25 - 19}{6} = \frac{6}{6} = 1\) - г) \(3\frac{1}{4} - 1\frac{5}{6}\)
\(3\frac{1}{4} - 1\frac{5}{6} = \frac{13}{4} - \frac{11}{6} = \frac{39}{12} - \frac{22}{12} = \frac{17}{12} = 1\frac{5}{12}\) - д) \(\frac{3}{8}\) · \(2\frac{2}{7}\) · \(\frac{2}{3}\)
\(\frac{3}{8}\) · \(\frac{16}{7}\) · \(\frac{2}{3}\) = \(\frac{3 \cdot 16 \cdot 2}{8 \cdot 7 \cdot 3}\) = \(\frac{1 \cdot 2 \cdot 2}{1 \cdot 7 \cdot 1}\) = \(\frac{4}{7}\) - е) \(1\frac{3}{7}\) : 10
\(\frac{10}{7}\) : 10 = \(\frac{10}{7}\) · \(\frac{1}{10}\) = \(\frac{1}{7}\) - ж) \(\frac{8}{9}\) : \(\frac{16}{27}\)
\(\frac{8}{9}\) · \(\frac{27}{16}\) = \(\frac{8 \cdot 27}{9 \cdot 16}\) = \(\frac{1 \cdot 3}{1 \cdot 2}\) = \(\frac{3}{2}\) = 1,5\) - з) \(2\frac{2}{3}\) : \(\frac{8}{9}\)
\(\frac{8}{3}\) : \(\frac{8}{9}\) = \(\frac{8}{3}\) · \(\frac{9}{8}\) = \(\frac{1 \cdot 3}{1 \cdot 1}\) = 3\) - и) \((1\frac{17}{25} \cdot 2\frac{7}{17} - 2\frac{4}{7} \cdot 1\frac{1}{5}) \cdot 2\frac{7}{9}\)
\((1\frac{17}{25} \cdot 2\frac{7}{17} - 2\frac{4}{7} \cdot 1\frac{1}{5}) \cdot 2\frac{7}{9}\) = \((\frac{42}{25} \cdot \frac{41}{17} - \frac{18}{7} \cdot \frac{6}{5}) \cdot \frac{25}{9}\)
Ответ: а) \(3\frac{5}{6}\); б) \(1\frac{3}{7}\); в) 1; г) \(1\frac{5}{12}\); д) \(\frac{4}{7}\); е) \(\frac{1}{7}\); ж) \(1,5\); з) 3; и) ...