## KingJ 3 years ago What is the sum of the arithmetic sequence 8, 14, 20 …, if there are 24 terms?

S = 2a + (n-1)d Where a = first number in sequence, n is nth term you are looking for and d is the common difference.

sorry, it should be: S = n/2( 2a + (n-1)d)

3. Mertsj

$s _{n}=\frac{n}{2}(a _{1}+a _{n})$ To find the 24th term use: $a _{n}=a _{1}+(n-1)d=8+(24-1)6=146$ $s _{n}=\frac{24}{2}(6+146)$ $s _{n}=1824$

4. Mertsj

There. I think I finally got it right.

5. KingJ

THANK YOU

6. Mertsj

yw

7. cinar

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8. cinar

1848

9. cinar

you put a1=6 but it is 8

10. cinar

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