What is the sum of the arithmetic sequence 6, 14, 22 , if there are 26 terms?

2,754

2,756

2,758

2,760

Question

What is the sum of the arithmetic sequence 6, 14, 22 , if there are 26 terms? 

2,754
		
2,756
		
2,758
		
2,760

campbell_st · Answer

the common difference d = 8 n = 26 and a = 6

then $$s _{n} = \frac{n}{2}(2a + (n -1) d)$$

substitute into the formula and evaluate... 

it may help to remember the formula.

parthkohli · Answer

First, find the 26th term.

$\Large \color{MidnightBlue}{\Rightarrow a_{n} = a_{1} + (n - 1)d }$

Then, see what the sum is.

$\Large \color{MidnightBlue}{\Rightarrow S_{n} = {n \over 2}(a_{1} + a_{l}) }$
a1 = first term
aL = last term

anonymous · Answer

checkout the attachment