Завдання 1301 - 1401 » 1321

Обчисліть: 1) –5/7 ∙ (–1,4) ∙ 31/2 ∙ 2/7 = – 5/7 ∙ (–7/5) ∙ 7/2 ∙ 2/7 = 1; 2) –3/11 ∙ (–2/15) ∙ 7 1/3 ∙ (–6) ∙ 40 = 3/11 ∙ (–2/15) ∙ 22/3 ∙ 6 ∙ 40 = –64; 3) –5 ∙ (–4) ∙ (–3) ∙ (–1) ∙ (1/3 ∙ 1/4 ∙ 1/5) = (5 ∙ 1/5) ∙ (4 ∙ 1/4) ∙ (3 ∙ 1/3) ∙ 1 = 1; 4) 4,2 ∙ (–1/35) + 121/169 ∙ (–12/11) – (–3) ∙ 1/25 = 21/5 ∙ (–1/35) + 121/169 ∙ (–13/11) + 3/25 = – 3/25 – 11/13 + 3/25 = – 11/13; 5) (–5)2 – (–4,2)2 + (–0,07) ∙ (–5/28) = 25 – 17,64 + 7/100 ∙ 5/7 = 7,36 + 1/20 = 7,36 + 0,05 = 7,41; 6) (5 ∙ (–7) + 4) ∙ |–0,9 + 5 ∙ 0,15| = (–35 + 4) ∙ |–0,9 + 0,75| = = –31 ∙ 0,15 = –4,65.