Question

I Need help on solving this arithmetic sequence......
a1=10, d=5; find a13

Answer 1

\[a_n= a_1 +(n-1)d\]\[\Large a_{13}=a_1 + (13-1)d=a_1 + 12d\]

Answer 2

What about the d=5 part . or is that the answer ??

Answer 3

You have to substitute the value in a1+ 12d ( a1=10 ,d=5)

Answer 4

thank you

Answer 5

Anytime :)

so what is your answer?

Answer 6

idk im horrible at math ...

Answer 7

a13=a1+12d
=10 + (12 x 5)
= ?

Answer 8

70?

Answer 9

Yes :)


Remember a_n= a1 + (n-1)d

Answer 10

thank you..

Answer 11

:)

Answer 12

So a13 = 70?

Answer 13

Yes

Answer 14

ok what about this one? : a1=6, d=9 find a8

Answer 15

a1=6, d=9 find a8

Answer 16

so what is the equation ,i just gave you that in the beginning

Answer 17

idk ... =\ . pleasee helpppp!

Answer 18

\[a_n=a_1 + (n-1)d\]
here n is 8

Answer 19

an=a1+(8−1)d

Answer 20

yes!! so ...

Answer 21

a8=a1+(8−1)d

Answer 22

Need some more help. ..! =\ don't remember what's next.

Answer 23

a8=a1+(8−1)d
=a1+7d

Answer 24

a8=8
???

Answer 25

how?

Answer 26

1+7=8

Answer 27

Noo

what is a1 & d given in question ?

a8=a1 + 7(d)

Answer 28

i don't know... =\ hmmph , i feel stupid .