Question

Which is the 25th term of the arithmetic sequence where a1 = 7 and a9 = 47

Answer 1

The common difference is 40/8 = 5
The formula:

\(\Large \color{Black}{\Rightarrow a_{n} = a_{1} + (n - 1)d }\)

Here:

\(\Large \color{Black}{\Rightarrow a_{25} = 7 + 5(24 - 1) }\)

Answer 2

first find common difference = ( a9 - a1) / 8
then use formula for 25the term

Answer 3

is it 122??

Answer 4

Yes.

Answer 5

:P

Answer 6

but thats not in my answers:(

Answer 7

7 + 5*24

Answer 8

Wouldn't it be 5 * 23?

Answer 9

25th term = a1 + 24d

Answer 10

its 127,

Answer 11

Oh sorry lol

Answer 12

right

Answer 13

(n - 1)d

Answer 14

24 * d

Answer 15

yea

Answer 16

Lol I got confused by myself

Answer 17

that happens - none of us are computers!!!

Answer 18

Hehe lol thanks

Answer 19

haha thanks can you help me with this ,What is the 8th term of the geometric sequence where a1 = 1024 and a3 = 64, and its no worries (:

Answer 20

i can but the moderators like you to post another question separately

Answer 21

best to do that, i think