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# Very Quick Question Please Need Help! watch

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1. This is a very easy question but dont no how to do it. I have been given a question on sequences and series, it is:
10
(3r+2)
r=5

now I no how to work it out when r=1 but don't no how to do it when r=5. I no the answer is 147, can somebody please explain how I get to that. Many Thanks
2. just write out the first three term and treat it like a normal arithmetic sequence.
Be careful about what n is (number of terms)
3. you can rewrite it as

4. you need to use the formula:

0.5n(a+l)
5. the numbers above and below that sign tells you what numbers to put into the equation. i think

so basically you put the numbers 5-10 into the equations to get 32+29+26+23+20+17
which equals 147.
6. why is everyone confusing him?

just use:

n=number of numbers in the sequence, which is 6 because you have 5th 6th 7th 8th 9th and 10th values to cater for
a=first term which you find by putting r=5
L = last term which you put r =10

therefore

put that into
the equation you're meant to know!

excersize 6G 2.d) ?
7. (Original post by Sparrow Hawk)
the numbers above and below that sign tells you what numbers to put into the equation. i think

so basically you put the numbers 5-10 into the equations to get 32+29+26+23+20+17
which equals 147.
But I cannot do this because I have a exam question that is:
200
(5r-2)
r=5

So how would I work out this? I only wanted to no that question I gave so i could work out this question myself, but it didnt help. Anybody no how I could work this out?
8. (Original post by neomilan)
why is everyone confusing him?

just use:

n=number of numbers in the sequence, which is 6 because you have 5th 6th 7th 8th 9th and 10th values to cater for
a=first term which you find by putting r=5
L = last term which you put r =10

therefore

put that into
the equation you're meant to know!

excersize 6G 2.d) ?
Perfect got it now

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Updated: November 16, 2008
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