482. Выполните умножение: a) 4x ⋅ 7y; б) -8x ⋅ 5x³; в) 4/9 ab³ ⋅ 3/2 ab; г) x²y⁵ ⋅ (-6xy²); д) -0,6a²b ⋅ (-10ab²); е) -1/5 m³n⁴ ⋅ 5m²n³.

Применим протокол Я.

1. a) 4x ⋅ 7y = 4 ⋅ 7 ⋅ x ⋅ y = 28xy
2. б) -8x ⋅ 5x³ = -8 ⋅ 5 ⋅ x ⋅ x³ = -40x^(1+3) = -40x⁴
3. в) $$\frac{4}{9}ab^3 \cdot \frac{3}{2}ab = \frac{4 \cdot 3}{9 \cdot 2} a^(1+1) b^(3+1) = \frac{2}{3} a^2 b^4$$
4. г) $$x^2y^5 \cdot (-6xy^2) = -6 x^(2+1) y^(5+2) = -6 x^3 y^7$$
5. д) $$-0,6a^2b \cdot (-10ab^2) = -0,6 \cdot (-10) a^(2+1) b^(1+2) = 6 a^3 b^3$$
6. e) $$\frac{-1}{5}m^3n^4 \cdot 5m^2n^3 = \frac{-1 \cdot 5}{5} m^(3+2) n^(4+3) = -1 m^5 n^7 = -m^5 n^7$$

Ответ:

1. 28xy
2. -40x⁴
3. $$\bf{\frac{2}{3} a^2 b^4}$$
4. -6 x³ y⁷
5. 6 a³ b³
6. -m⁵ n⁷