Question

Решите по формуле фсу
2х^3+8у^3=

3а^3-2в=

Answer 1

Ответ:

$2x^3+8y^3=2(x^3+4y^3)=2(x+\sqrt[3]4y)(x^2-2\sqrt[3]4xy+\sqrt[3]{16}y^2)\\\\\\3a^3-2b=(\sqrt[3]3a)^3-(\sqrt[3]{2b})^3=(\sqrt[3]3a+\sqrt[3]{2b})(\sqrt[3]9a^2-\sqrt[3]{6ab}+\sqrt[3]{4b^2})\\\\\\P.S.\ \ \ p^3\pm q^3=(p\pm q)(p^2\mp pq+q^2)$