Решебник по математике 6 класс Ерина Виленкин рабочая тетрадь Часть 1, 2 Часть 2 | Страница 65

\[Стр.\ 65.\]

\[\boxed{\mathbf{7.}}\]

\[\textbf{б)} - 5 \cdot 7 \cdot ( - 20) \cdot 13 =\]

\[= - 5 \cdot ( - 20) \cdot 7 \cdot 13 =\]

\[= 100 \cdot 91 = 9100\]

\[\textbf{в)}\frac{11}{4} \cdot \left( - \frac{2}{3} \right) \cdot \left( - \frac{4}{11} \right) =\]

\[= \left( \frac{11}{4} \cdot \left( - \frac{4}{11} \right) \right) \cdot \left( - \frac{2}{3} \right) =\]

\[= - 1 \cdot \left( - \frac{2}{3} \right) = \frac{2}{3}\]

\[\textbf{г)}\frac{13}{17} \cdot \left( - \frac{10}{11} \cdot \frac{17}{13} \right) =\]

\[= \left( \frac{13}{17} \cdot \frac{17}{13} \right) \cdot \left( - \frac{10}{11} \right) = - \frac{10}{11}\]

\[\textbf{д)} - \frac{21}{50} \cdot \left( - \frac{50}{21} \cdot \frac{2}{13} \right) =\]

\[= \left( - \frac{21}{50} \cdot \left( - \frac{50}{21} \right) \right) \cdot \frac{2}{13} =\]

\[= 1 \cdot \frac{2}{13} = \frac{2}{13}\]

\[\textbf{е)}\frac{15}{26} \cdot \left( - \frac{12}{19} \cdot \frac{26}{15} \right) =\]

\[= \frac{15}{26} \cdot \frac{26}{15} \cdot \left( - \frac{12}{19} \right) =\]

\[= 1 \cdot \left( - \frac{12}{19} \right) = - \frac{12}{19}\]

\[\textbf{ж)} - 0,5 \cdot 2\frac{1}{7} \cdot ( - 2) \cdot \left( - \frac{7}{15} \right) =\]

\[= - 0,5 \cdot ( - 2) \cdot 2\frac{1}{7} \cdot \left( - \frac{7}{15} \right) =\]

\[= 1 \cdot ( - 1) = - 1\]

\[\textbf{з)} - 25 \cdot 1,34 \cdot ( - 4) \cdot ( - 1) =\]

\[= - 25 \cdot ( - 4) \cdot 1,34 \cdot ( - 1) =\]

\[= 100 \cdot ( - 1,34) = - 134\]

\[\boxed{\mathbf{8.}}\]

\[\textbf{а)}\ 17 + a + 24 - a = 41\]

\[\textbf{б)}\ 5y + b + 10 - b - 10 = 5y\]

\[\textbf{в)}\ 2\frac{1}{7} + x - y + 10\frac{6}{7} - x + y =\]

\[= 13\]

\[\textbf{г)}\ 0,29 - x - a + 0,71 + x + a =\]

\[= 1\]