Вправи 1001 - 1100 » 1079

Знайдіть значення виразу: 1) 7(3 – 4b) – 5(3b + 4) = 21 – 28b – 15b – 20 = –43b + 1. При b = –0,2; –43b + 1 = –43 ∙ (–0,2) + 1 = 8,6 + 1 = 9,6. 2) –214/13(13 – p) + 11/13(26 – p) = –30/13(13 – p) + 14/13(26 – p) = –30 + 30/13p + 28 – 14/13p = 16/13p – 2. При p = 31/4p; 16/13p – 2 = 16/13 ∙ 13/4 – 2 = 4 – 2 = 2.