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# Arithmetic sequences

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1. https://a9497d7f220e174d38d014b2b1d8...%20Edexcel.pdf

Question 7 a, i have no idea what to do help pls
2. Arithmetic sequences increase by the same value in between terms. So term2 - term1 = term3 - term2. Apply that logic to this question and you have an equation in terms of p, then rearrange and solve.
3. (Original post by thefatone)
https://a9497d7f220e174d38d014b2b1d8...%20Edexcel.pdf

Question 7 a, i have no idea what to do help pls
What do you know about arithmetic seqeunces? They have a common difference.

What does the word difference mean? It means the second term minus the first term or the third term minus the second term, etc...

Essentially, the difference between terms have to be the same.

What is the difference between the first two terms in terms of ?

What is the difference between the third and second term in terms of ?

Equate them and solve for .
4. Lets say you are given 3 terms: a ar ar^2

The rule that you would apply to find the value of r would be:
ar/a = ar^2/ar
Then you would just solve it for r.

The same rule applies to the values they have given you.

2p/(12-p) = (4p-5)/2p
Solve this to get p. Hope that helps
5. (Original post by Miningstew)
Arithmetic sequences increase by the same value in between terms. So term2 - term1 = term3 - term2. Apply that logic to this question and you have an equation in terms of p, then rearrange and solve.
Thanks a ton
(Original post by Zacken)
What do you know about arithmetic seqeunces? They have a common difference.

What does the word difference mean? It means the second term minus the first term or the third term minus the second term, etc...

Essentially, the difference between terms have to be the same.

What is the difference between the first two terms in terms of ?

What is the difference between the third and second term in terms of ?

Equate them and solve for .
Thanks so much i have no idea what i'd do without you guys ^-^
(Original post by Filipo)
Lets say you are given 3 terms: a ar ar^2

The rule that you would apply to find the value of r would be:
ar/a = ar^2/ar
Then you would just solve it for r.

The same rule applies to the values they have given you.

2p/(12-p) = (4p-5)/2p
Solve this to get p. Hope that helps
ummm no that's for common ratio's not for sequences which go up by a regular amount
6. (Original post by Filipo)
Lets say you are given 3 terms: a ar ar^2

The rule that you would apply to find the value of r would be:
ar/a = ar^2/ar
Then you would just solve it for r.

The same rule applies to the values they have given you.

2p/(12-p) = (4p-5)/2p
Solve this to get p. Hope that helps
That's a geometric sequence that you're talking about. This is clearly stated as an arithmetic sequence.
7. (Original post by Zacken)
That's a geometric sequence that you're talking about. This is clearly stated as an arithmetic sequence.
8. (Original post by Filipo)
Yeah, I've had many a moment too, don't worry.
9. you should get 3p-12 as the difference right?

and then p=7?
10. (Original post by richpanda)
and then p=7?
Correct.

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