Используем формулы суммы и разности кубов:
$$a^3 + b^3 = (a + b)(a^2 - ab + b^2)$$ и $$a^3 - b^3 = (a - b)(a^2 + ab + b^2)$$
1) $$a^3 + 1 = (a + 1)(a^2 - a + 1)$$
2) $$m^3 + 27 = (m + 3)(m^2 - 3m + 9)$$
3) $$64y^3 - x^3 = (4y - x)(16y^2 + 4xy + x^2)$$
4) $$216 + m^3n^3 = (6 + mn)(36 - 6mn + m^2n^2)$$
5) $$a^6 - b^{12} = (a^2)^3 - (b^4)^3 = (a^2 - b^4)(a^4 + a^2b^4 + b^8) = (a - b^2)(a + b^2)(a^4 + a^2b^4 + b^8)$$
6) $$343a^3b^6 + 0,027c^9d^{21} = (7ab^2)^3 + (0,3c^3d^7)^3 = (7ab^2 + 0,3c^3d^7)(49a^2b^4 - 2,1ab^2c^3d^7 + 0,09c^6d^{14})$$