ЧАСТИНА 2 - Вправи: 1305

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) 23(1,8 – 114m) – 213(1,2 – 514m) = 2 ∙ 93 ∙ 5 – 2 ∙ 53 ∙ 4m – 7 ∙ 63 ∙ 5 + 7 ∙ 53 ∙ 14m = 65 – 56m – 4215+ 56m = 18 - 4215 = -2415 = –135 = –1,6.