Mathematics, 29.06.2019 22:00, discolldiane7351
The sum of the first n terms of an a. p. is 2n and the sum of the first 2n terms is n. find the sum of the first 4n terms.
Answers: 1
![S_n=\frac{n}{2}[2a+(n-1)d]](/tpl/images/0032/5459/b603c.png)
![\frac{n}{2}[2a+(n-1)d]=2n](/tpl/images/0032/5459/6b2b7.png)
..... (1)![\frac{2n}{2}[2a+(2n-1)d]=n](/tpl/images/0032/5459/8fffa.png)
..... (2)
![S_{4n}=\frac{4n}{2}[2a+(4n-1)d]](/tpl/images/0032/5459/2df69.png)
![S_{4n}=2n[2a+(4n-1)d]](/tpl/images/0032/5459/13810.png)
![S_{4n}=2n[2(\frac{1}{2}(7-\frac{3}{n}))+(4n-1)(-\frac{3}{n})]](/tpl/images/0032/5459/ab54b.png)
![S_{4n}=2n[7-\frac{3}{n}-12+\frac{3}{n}]](/tpl/images/0032/5459/8d596.png)
![S_{4n}=2n[-5]](/tpl/images/0032/5459/a584a.png)
Other questions on the subject: Mathematics
Mathematics, 21.06.2019 20:20, kenken2583
Complete the input-output table for the linear function y = 3x. complete the input-output table for the linear function y = 3x. a = b = c =
Answers: 2
Mathematics, 21.06.2019 23:30, Dragonskeld
Is the underlined participial phrase correctly placed or misplaced? i smelled each and every flower strolling through the garden. a. correctly placed participial phrase b. misplaced participial phrase
Answers: 2
Mathematics, 22.06.2019 01:00, pineapplepizaaaaa
Which number produces an irrational number multiplied by 1/3
Answers: 1
Do you know the correct answer?
The sum of the first n terms of an a. p. is 2n and the sum of the first 2n terms is n. find the sum...
Questions in other subjects:
Mathematics, 13.04.2021 03:00
Mathematics, 13.04.2021 03:00
Mathematics, 13.04.2021 03:00
World Languages, 13.04.2021 03:00
