## maria-17 2 years ago Please help What is the sum of the arithmetic sequence 134, 122, 110 …, if there are 32 terms?

1. tpaulus

Find the general form, then use that to find the last term. then use the sum of an arithmetic sequence equation to find the sum.$s = n/2 * (n1 + n32)$

2. campbell_st

well the sum is simply $S_{n} = \frac{n}{2}[2a + (n -1)d]$ a = 1st term, n = number of terms and d = common difference in your question you know n = 32, the 1st term is 134 find the common difference. ..d and then substitute and evaluate. the value of d will be negative

3. maria-17

–1,664 –1,632 –1,600 –1,568

4. maria-17

5. tcarroll010

S = [134 - (0)(12)] + [134 - (1)(12)] + [134 - (2)(12)] + . . . + [134 - (31)(12)] S = (134)(32) - (12)(1 + 2 + 3 + . . . + 31) S = (134)(32) - (12)(31)(32)/2

6. tcarroll010

All good now, @maria-17 ?

7. maria-17

THanksss.

8. tcarroll010

uw!

9. tcarroll010

Good luck to you in all of your studies and thx for the recognition! @maria-17

10. maria-17

Can you help me with one more?

11. tcarroll010

Sure, why not? Best though to close this one and just start another post.