Question

4th term of an arithmetic sequence is 23 and its 11th term is 65, what is its common difference​

Answer 1

Answer:

d = 6

Step-by-step explanation:

The nth term of an arithmetic sequence is

$a_{n}$ = a₁ + (n - 1)d

where a₁ is the first term and d the common difference

Given a₄ = 23 and a₁₁ = 65 , then

a₁ + 3d = 23 → (1)

a₁ + 10d = 65 → (2)

Subtract (1) from (2) term by term to eliminate a₁

10d - 3d = 65 - 23

7d = 42 ( divide both sides by 7 )

d = 6