ЧАСТИНА 2 - Вправи: 1271

1271. Розкрий дужки та обчисли:

1) (18 – 12) · 8 = 18 · 8 – 12 · 8 = 1 – 4 = –3;

2) –15 · (13 – 15) = –15 · 13 – 15 · (–15) = – 5 + 3 = –2;

3) 9 · (19 – 13 + 1) = 9 · 19 – 9 · 13 + 9 · 1 = 1 – 3 + 9 = 7;

4) (–117 + 134) · 34 = – 117 · 34 + 134 · 34 = – 2 + 1 = – 1;

5) (120 + 110 – 15) · (–20) = 120 · (–20) + 110 · (–20) – 15 · (–20) = –1 – 2 + 4 = 1;

6) 15 · (–13 – 15 – 115) = 15 · (–13) + 15 · (–15) + 15 · (–115) = –5 – 3 – 1 = –9.