a/ $(x+4)^3\\=x^3+3.x^2.4+3.x.4^2+4^3\\=x^3+12x^2+48x+64$
$(2x+y)^3\\=(2x)^3+3.(2x)^2.y+3.2x.y^2+y^3\\=8x^3+12x^2y+6xy^2+y^3$
b/ $(2x-1)^3\\=(2x)^3-3.(2x)^2.1+3.2x.1^2-1^3\\=8x^3-12x^2+6x-1$
$(3x-2y^3)^3=(3x)^3-3.(3x)^2.2y^3+3.3x.(2y^3)^2-(2y^3)^3\\=27x^3-54x^2y^3+36xy^6-8y^9$
c/ $(x+1)(x^2-x+1)\\=(x+1)(x^2-x.1+1^2)\\=x^3-1^3\\=x^3-1$
d/ $(x-3)(x^2+3x+9)\\=(x-3)(x^2+3x+3^2)\\=x^3-3^3\\=x^3-27$