2. Найдите значение выражения: a) -34 + 18+ (-20) + (-16) + 42; 4 3 7 б) --5-8-; · 7 6 в) -13 3,8-3,8-. 7 13

1. a) -34 + 18 + (-20) + (-16) + 42 = -34 + 18 - 20 - 16 + 42 = -10
2. б)
   Показать решение

   \(-\frac{4}{7}\) ⋅ 5\(\frac{3}{8}\) ⋅ \(\frac{7}{4}\) = -\(\frac{4}{7}\) ⋅ \(\frac{43}{8}\) ⋅ \(\frac{7}{4}\) = -\(\frac{4 ⋅ 43 ⋅ 7}{7 ⋅ 8 ⋅ 4}\) = -\(\frac{1 ⋅ 43 ⋅ 1}{1 ⋅ 2 ⋅ 1}\) = -\(\frac{43}{2}\) = -21\(\frac{1}{2}\)
3. в)
   Показать решение

   -\(\frac{6}{13}\) ⋅ 3,8 - 3,8 ⋅ \(\frac{7}{13}\) = 3,8 ⋅ (- \(\frac{6}{13}\) - \(\frac{7}{13}\)) = 3,8 ⋅ (- \(\frac{6+7}{13}\)) = 3,8 ⋅ (- \(\frac{13}{13}\)) = 3,8 ⋅ (-1) = -3,8

Ответ: a) -10; б) -21 \(\frac{1}{2}\); в) -3,8