## Poleng_InLove 2 years ago There are three terms in Arithmetic Sequence . The common difference is 11 . A1=n-5 , A2=n-1 , and A3=2n . What are the terms ?

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1. hartnn

common difference = A2-A1 = A3-A2 = 11

2. hartnn

A3-A2 = 11 2n - (n-1) =11 can you find 'n' from here ??

3. Poleng_InLove

Hmm ...

4. hartnn

was that a yes or no ?? O.o

5. Poleng_InLove

Wait .

6. hartnn

waiting...

7. agent0smith

A2 - A1 = 11 (n - 1) - (n -5) = 11 -1 + 5 = 11 no. 4 does not equal 11.

8. hartnn

ok...i guess, 11 as common difference(d) should naot have been given. in that case d = A2 - A1 = 4 then A3-A2 = 4 and find 'n'.

9. Poleng_InLove

How can I find the n ?

10. derek123

why 4 again??

11. hartnn

common diff. always remains constant/same!

12. hartnn

2n - (n-1) =4

13. hartnn

n+1=4

14. derek123

n=5??

15. hartnn

is 5+1 = 4 ??

16. Poleng_InLove

n=3 ?

17. hartnn

yes. n=3 :)

18. agent0smith

Yep, common difference of 4 works here.

19. Poleng_InLove

n-5=-2 n-1=2 2n=6

20. hartnn

\(\checkmark \)

21. derek123

haha i used this d = A2 - A1 = 4

22. agent0smith

Note that we can't guarantee these are the correct answers, since... the question claims the difference is 11. Either that's wrong, or you didn't write out the question correctly.

23. Poleng_InLove

That's okay :))

24. derek123

WHAT IF THE COMMON DIFFERENCE IS 9??

25. hartnn

from d = A2 - A1 the common diff. must be 4 cannot be anything else.

26. derek123

OH WELL. xD

27. hartnn

did you ppl start learning sequences ??

28. derek123

yup,xD arithmetic seq and series and mean and geom seq and series

29. derek123

the formulae actually are mixing in my head. O_o

30. hartnn

31. agent0smith

\[\large{\color{Blue}{T}\color{Yellow}{U}\color{Magenta}{T}\color{Pink}{O}\color{MidnightBlue}{R} I\color{Blue}{A}\color{Green}{L}!}\] ^^ Is it a tutorial on how to have a seizure? :P

32. amistre64

nice "tutorial" :)