Вправи: 258

258. Спростіть вираз:

1) 3a ∙ (–1,2)=3 ∙(–1,2) ∙ a = –3,6a;

2) –0,2b ∙ (–0,5) = –0,2 ∙ (–0,5) ∙ b = 0,1b;

3) –7a ∙ 9b = –7 ∙ 9 ∙ ab = –63ab;

4) 2,4x ∙ 2y = 2,4 ∙ 2 ∙ xy = 4,8xy;

5) –314m ∙ 79n =–314 ∙ 79 ∙ mn = –16mn;

6) –14a ∙ 43b ∙ (–3c) = –14 ∙ 43 ∙ (–3)abc = abc