D = (2n + 1)(n² - 3n - 1) - 2n³ + 1.5, (∀n ∈ ℤ)

----- Nội dung ảnh -----
D = (2n + 1)(n² - 3n - 1) - 2n³ + 1.5, (∀n ∈ ℤ)

E = [ (n - 1)(n + 1) - (n - 7)(n - 5) ] : 12, (∀n ∈ ℤ)

F = (6n + 1)(n + 5) - (3n + 5)(2n - 1) : 2, (∀n ∈ ℤ)

G = (5a - 3)(3b - 5) - (3a - 5)(5b - 3) : 16, (∀a, b ∈ ℝ)