решите плиз: (^ - степень) 1)a^3+8b^3; 2)x^2y-36y^3; 3)-5m^2+10mn-5n^2; 4)4ab-28b+8a-56; 5)a^4-81. Created by mrfresh132. algebra-ru

решите плиз: (^ - степень) 1)a^3+8b^3; 2)x^2y-36y^3; 3)-5m^2+10mn-5n^2; 4)4ab-28...

ЯгодкаЯлесная A³ + 8b³ = a³ + (2b)³ = (a + 2b)(a² - 2ab + 4b²)

x²y - 36y³ = y(x² - 36y²) = y(x - 6y)(x + 6y)

- 5m² + 10mn - 5n² = - 5(m² - 2mn + n²) = - 5(m - n)² = - 5(m - n)(m - n)

4ab - 28b + 8a - 56 = (4ab - 28b) + (8a - 56) = 4b(a - 7) + 8(a - 7) =
= (a - 7)(4b + 8) = 4(a - 7)(b + 2)

a⁴ - 81 = a⁴ - 3⁴ = (a²)² - (3²)² = (a² - 3²)(a² + 3²) = (a² - 9)(a² + 9) =
= (a - 3)(a + 3)(a² + 9)

mrfresh132 спасибо тебе