д) $$(2x + y)^3 - (2x - y)^3$$
$$= ((2x + y) - (2x - y))((2x + y)^2 + (2x + y)(2x - y) + (2x - y)^2)$$
$$= (2x + y - 2x + y)(4x^2 + 4xy + y^2 + 4x^2 - y^2 + 4x^2 - 4xy + y^2)$$
$$= 2y(12x^2 + y^2)$$
Ответ: $$2y(12x^2 + y^2)$$
e) $$(4x + 5y)^2 + 4x + 5y$$
$$=(4x+5y)(4x+5y)+ 4x + 5y=(4x+5y)(4x+5y+1)$$
Ответ: $$(4x+5y)(4x+5y+1)$$