Question

Find the value of x if each sequence is arithmetic :
2, 8, 3x + 5

Answer 1

what is an arithmetic sequence?

Answer 2

a sequence with common difference between two terms consecutive always fixed.

Answer 3

so, what is the common difference in your sequence?

Answer 4

it doesn't mention. what do you think? is that arithmetic sequence or not ? or can we find out the value of x ?

Answer 5

To find the common difference, subtract the first term from the second term. What do you get?

Answer 6

I get it, the common diffrence is 6, so I find the value of x is 3. do you think is that true ?

Answer 7

That is correct. Good job.

Answer 8

but I still have one question more, please help me ok.
how to find out the value of x. 4, x, 3/2 x

Answer 9

Is this supposed to be another arithmetic sequence?

Answer 10

@sofiah post the original question with all of its conditions, please

Answer 11

find the value of x if each sequences is arithmetic.
a. 2, 8, 3x + 5
b. 4, x, 3/2 x

Answer 12

I think b is geometric sequences.

Answer 13

there is a way to find out x if it's an arithmetic sequence. If you said that it's, stick with it and solve for x. Okay, which one do you want to do? geo or arith?

Answer 14

cannot "think" friend, base on the question from book, please!!

Answer 15

ok. so how the way to find out the value of x?

Answer 16

find out the difference again.!!

Answer 17

let d be the difference, so x - 4=d ok?

Answer 18

got it??

Answer 19

not yet, I still try to find out.

Answer 20

Why do you think b is geometric when the problem says "each sequence is arithmetic"?

Answer 21

So as Loser66 says, the common difference is x-4. Add x-4 to the second term, which is x and you will get the third term. Write and solve that equation.

Answer 22

I get the value of x is 8. is that correct?

Answer 23

yes

Answer 24

ok. thanks a lot for your helps.

Answer 25

yw