Question

The first term of an arithmetic sequence is 6 and common difference is 4.what is the algebraic expression to find the sum of the first n terms of this sequence?

Answer 1

Answer:

2 n² + 4 n

Step-by-step explanation:

Given :

First term = 6

Common difference = 4

We know :

S_n = n / 2 [ 2 a + ( n - 1 ) d ]

S_n = n / 2 [ 12 + 4 ( n -1 ) ]

S_n = n [ 6 + 2 ( n - 1 ) ]

S_n = n ( 2 n + 4 )

S_n = 2 n² + 4 n

Therefore ,  sum of the first n terms of this sequence in algebraic expression as  2 n² + 4 n .