Завдання 1201 - 1300 » 1272

Розкрий дужки: 1) –0,8a · (–4b + 3c – 0,9d) = –0,8a · (–4b) – 0,8a · 3c – 0,8a · (–0,9d) = 3,2ab – 2,4ac + 0,72ad; 2) (0,7x – 2,5y – 3,8z) · (–0,4) = 0,7x · (–0,4) – 2,8y · (–0,4) – 3,8z∙ · (–0,4) = –0,28x + y + 1,52z; 3) –12 · (15/6t – 11/3b + 21/2z) = –12 · 11/6t – 12 · (– 4/3b) – 12 · 5/2z = –22t + 16b – 30z; 4) (–1/7y + 11/2z – 21/14t) · 14x = – 1/7y · 14x + 3/2z · 14x – 29/14t · 14x = –2xy + 21zx – 29tx.