Завдання 1301 - 1401 » 1323

Знайдіть 20 % числа х, якщо: 1) x = –10,5 ∙ 22/15 + (–5,4) ∙ 37/9 – 108/285 ∙ (–19/144) = –21/2 ∙ 32/15 – 27/5 ∙ 34/9 + 108/285 ∙ 19/144 = –112/5 – 102/5 + 3/60 = –22,4 – 20,4 + 0,05 = –42,75; 0,2x = –42,75 ∙ 0,2 = –8,55; 2) x = 1,8 ∙ (–42/3) + 65/6 ∙ (–6/41) = 9/5 ∙ (–14/3) + 41/6 ∙ (–6/41) = –42/5 – 1 = –8,4 – 1 = –9,4; 0,2x = –9,4 ∙ 0,2 = –1,88.