Answer:
The answer is the last one:
4 , 10 , 18 , (k + 1)² + 3(k + 1) and k² + 5k + 4
Step-by-step explanation:
∵ 2 is a factor of n² + 3n
∵ n = 1 ⇒ ∴ (1)² + 3(1) = 1 + 3 = 4 ⇒ 2 is a factor of 4
∵ n = 2 ⇒ ∴ (2)² + 3(2) = 4 + 6 = 10 ⇒ 2 is a factor of 10
∵ n = 3 ⇒ ∴ (3)² + 3(3) = 9 + 9 = 18 ⇒ 2 is a factor of 18
∵ n = k + 1 ⇒ ∴ (k + 1)² + 3(k + 1) ⇒ before the simplify
∵ n = k + 1 ⇒ ∴ k² + 2k + 1 + 3k + 3 = k² + 5k + 4 ⇒ after simplify
