Завдання 1201 - 1300 » 1270

Розкрий дужки та обчисли: 1) 4 · (1/4 – 1/2) = 4 · 1/4 – 4 · 1/2 = 1 – 2 = –1; 2) (–1/7 + 1/14 – 1/42) · 42 = – 1/7 · 42 + 1/14 · 42 – 1/42 · 42 = –6 + 3 – 1 = –4; 3) 21 · (1/7 – 1/3 – 1) = 21 · 1/7 – 21 · 1/3 – 21 · 1 = 3 – 7 – 21 = –25; 4) –12 · (1/3 – 1/6) = –12 · 1/3 – 12 · (–1/6) = –4 + 2 = –2; 5) 18 · (1/9 – 1/2 – 1/3) = 18 · 1/9 – 18 · 1/2 – 18 · 1/3 = 2 – 9 – 6 = –13; 6) (1/25 – 1/2 – 1/5) · (–100) = 1/25 · (–100) – 1/2 · (–100) – 1/5 · (–100) = –4 + 50 + 20 = 66.