Завдання 1301 - 1402 » 1305

Спрости вираз: 1) (–1,8a + 2,5b) · 4 – 3(3,2a + 0,9b – 2) – (2,8a – 7) = –1,8a · 4 + 2,5b · 4 – 3 · 3,2a – 3 · 0,9b + 6 – 2,8a + 7 = –7,2a + 10b – 9,6a – 2,7b + 6 – 2,8a + 7 = –19,6a + 7,3b + 13; 2) 2/3(1,8 – 11/4m) – 21/3(1,2 – 5/14m) = (2 ∙ 9)/(3 ∙ 5) – (2 ∙ 5)/(3 ∙ 4)m – (7 ∙ 6)/(3 ∙ 5) + (7 ∙ 5)/(3 ∙ 14)m = 6/5 – 5/6m – 42/15+ 5/6m = (18 - 42)/15 = (-24)/15 = –13/5 = –1,6.