Tính
----- Nội dung ảnh -----
A = n(3n - 1) - 3n(n - 2): 5, (∀n ∈ ℝ)
B = n(n + 5) - (n - 3)(n + 2): 6, (∀n ∈ ℤ)
C = (n² + 3n - 1)(n + 2) - n³ + 2.5, (∀n ∈ ℤ)
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)
A = n(3n - 1) - 3n(n - 2): 5, (∀n ∈ ℝ)
B = n(n + 5) - (n - 3)(n + 2): 6, (∀n ∈ ℤ)
C = (n² + 3n - 1)(n + 2) - n³ + 2.5, (∀n ∈ ℤ)
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)