Вправи: 281

281. Виконайте множення:

1) 14m²n(2,4mn – 2,8m²) = 14m²n ∙ 2410mn – 14m²n ∙ 2810m² = 35m³n² – 710m⁴n;

2) –25ab³(1,5ab – 56b²) = –25ab³ ∙ 1510ab – (–25)ab³ ∙ 56b² = –35a²b⁴ + 13ab⁵;

3) (112x²y – 910xy⁴) ∙ 23xy³ = 32x²y ∙ 23xy³ – 910xy⁴ ∙ 23xy³ = x³y⁴ – 35x²y⁷;

4) (1,5a – 47b) ∙ (–114a²b⁵) = 1510a ∙ (–114a²b⁵) – 47b ∙ (–114a²b⁵) =

= –328a³b⁵ + 249a²b⁶.