Решебник по математике 5 класс Ткачева рабочая тетрадь | Страница 66

\[\boxed{\mathbf{2.}}\]

\[1)\ \frac{5^{\backslash 5}}{12} - \frac{2^{\backslash 4}}{15} = \frac{25 - 8}{60} = \frac{17}{60}\]

\[НОК(12,\ 15) = 60\]

\[2)\ \frac{23^{\backslash 2}}{30} - \frac{7^{\backslash 3}}{20} = \frac{46 - 21}{60} = \frac{25}{60}\]

\[НОК(30,\ 20) = 60\]

\[3)\ \frac{9^{\backslash 9}}{10} - \frac{28^{\backslash 2}}{45} = \frac{81 - 56}{90} = \frac{25}{90}\]

\[НОК(10,\ 45) = 90\]

\[\boxed{\mathbf{3.}}\]

\[1)\ 2\frac{3}{8} - 1\frac{7}{12} = \frac{19^{\backslash 3}}{8} - \frac{19^{\backslash 2}}{12} =\]

\[= \frac{57 - 38}{24} = \frac{19}{24}\]

\[НОК(8,\ 12) = 24\]

\[2)\ 4\frac{1}{6} - 2\frac{3}{10} = \frac{25^{\backslash 5}}{6} - \frac{23^{\backslash 3}}{10} =\]

\[= \frac{125 - 69}{30} = \frac{56}{30} = \frac{28}{15} = 1\frac{13}{15}\]

\[НОК(6,\ 10) = 30\]

\[\mathbf{39.\ Умножение\ дробей}\]

\[\boxed{\mathbf{1.}}\]

\[1)\frac{6}{11} \cdot \frac{5}{9} = \frac{6 \cdot 5}{11 \cdot 9} = \frac{30}{99} = \frac{10}{33}\]

\[2)\ \left( \frac{2}{5} \right)^{2} = \frac{2}{5} \cdot \frac{2}{5} = \frac{2 \cdot 2}{5 \cdot 5} = \frac{4}{25}\]

\[3)\ \left( 1\frac{1}{3} \right)^{3} = \left( \frac{4}{3} \right)^{3} = \frac{4}{3} \cdot \frac{4}{3} \cdot \frac{4}{3} =\]

\[= \frac{4 \cdot 4 \cdot 4}{3 \cdot 3 \cdot 3} = \frac{64}{27} = 2\frac{10}{27}\]

\[4)\ 3 \cdot \frac{7}{13} = \frac{3 \cdot 7}{13} = \frac{21}{13} = 1\frac{8}{13}\]

\[5)\ \frac{4}{9} \cdot 2 = \frac{4 \cdot 2}{9} = \frac{8}{9}\]