2. Выполните действие a) (2,9–4,7)⋅0,5; б) -\frac{2}{7}⋅14⋅(-\frac{7}{8}):(-4).

• a) (2,9 - 4,7) ⋅ 0,5 = -1,8 ⋅ 0,5 = -0,9
• б) -\frac{2}{7} ⋅ 14 ⋅ (-\frac{7}{8}) : (-4) = -\frac{2}{7} ⋅ 14 ⋅ (-\frac{7}{8}) ⋅ (-\frac{1}{4}) = -\frac{2 ⋅ 14 ⋅ 7}{7 ⋅ 8 ⋅ 4} = -\frac{2 ⋅ 2 ⋅ 7 ⋅ 7}{7 ⋅ 8 ⋅ 4} = -\frac{4 ⋅ 7}{8 ⋅ 4} = -\frac{7}{8} = -0,875

Ответ: a) -0,9; б) -0,875