Вправи 1001 - 1100 » 1072

Обчисліть найзручнішим способом: 1) 6,72 ∙ (21/3) + 3,72 ∙ 21/3 = 21/3 ∙ (–6,72 + 3,72) = 7/3 ∙ (–3) = –7; 2) –7,2 ∙ 22/15 – 7,2 ∙ 37/15 – 7,2 ∙ (–44/15) = –7,2 ∙ (22/15 + 37/15 + 44/15) = –36/5 ∙ 913/15 = – 1776/25 = –711/25; 3) –39/14 ∙ 0,3 – 0,3 ∙ (–110/21) + 0,3 ∙ 11/6 = 0,3 ∙ (–39/14 + 110/21 + 11/6) = 0,3 ∙ (–327/42 + 17/42) = 0,3 ∙ (–1) = –0,3.