So guys, I know some of you are pretty good with numbers.

I am stuck on this question for specialist mathematics, anyone help me? Ted, your up mate!

Question is as follows:

The sixth term of a sequence is 82 and the eleventh term is 62. Find the sum of the first 20 terms of the sequence. I can't find examples in our books of this and am a bit lost.

Any ideas guys? Ted?

I thought I could use simultaneous equations with the 82 and the 62 where the sum to n follows a, a+d, a+2d etc. Where a is the first term, a + d is the second term, a+2d is the 3rd term etc. Following this then the 6th term would be a+5d which is equal to 82, equation one, and the 11th term would be a+10d which is equal to 62, equation 2. Subract one from the other to eliminate one variable and then solve for both variables.

I thought this would give me my nth term but do not think it does.

This probably is straight over the head of some, straight over my head, almost, and my parents.

TED! You said you were good at maths, are you this good?

Cheers Breezers! Any help is appreciated!

Tom.

geez mate ..... well 4 sixpacks of full strength beer equals 1 carton or in layman's terms .... 24 stubs

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thePup said..

geez mate ..... well 4 sixpacks of full strength beer equals 1 carton or in layman's terms .... 24 stubs

So the question is effed? Agreed mate Oldmate should be able to answer this, this pre engineering maths!

Fark Tom, I think you just split the atom.

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NewScotty said..

Fark Tom, I think you just split the atom.

Haha, found this stuff relatively easy so far, it gets much much harder! Haha

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NewScotty said..

Fark Tom, I think you just split the atom.

Sweet jesus that avatar just gets better and better and better and .......

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thePup said..

NewScotty said..

Fark Tom, I think you just split the atom.

Sweet jesus that avatar just gets better and better and better and .......

You two are no help at all!

I think it's 69 !

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Teacake said..

thePup said..

NewScotty said..

Fark Tom, I think you just split the atom.

Sweet jesus that avatar just gets better and better and better and .......

You two are no help at all!

Yeh

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surfbroker said..

I think it's 69 !

Explain your working?

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thePup said...

NewScotty said..

Fark Tom, I think you just split the atom.

Sweet jesus that avatar just gets better and better and better and .......

Control yourself Pup.
We don't want that long red thing sticking out.

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NewScotty said..

thePup said...

NewScotty said..

Fark Tom, I think you just split the atom.

Sweet jesus that avatar just gets better and better and better and .......

Control yourself Pup.
We don't want that long red thing sticking out.

Come on guys, maths.

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Teacake said..

surfbroker said..

I think it's 69 !

Explain your working?

Well..it goes like this:
The square of the hypotanous is equal to the sum of the square of the other 2 sides= every action has an equal and opposite reaction=dinner for 2..
That explains it..

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surfbroker said..

Teacake said..

surfbroker said..

I think it's 69 !

Explain your working?

Well..it goes like this:
The square of the hypotanous is equal to the sum of the square of the other 2 sides= every action has an equal and opposite reaction=dinner for 2..
That explains it..

Lol, dinner for 2... $h!t! Forgot! The missus text me before and said, What happened to dinner? I am up $h!t creek without a paddle now for sure!

Now you know whats on the menu

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Teacake said..

surfbroker said..

Teacake said..

surfbroker said..

I think it's 69 !

Explain your working?

Well..it goes like this:
The square of the hypotanous is equal to the sum of the square of the other 2 sides= every action has an equal and opposite reaction=dinner for 2..
That explains it..

Lol, dinner for 2... $h!t! Forgot! The missus text me before and said, What happened to dinner? I am up $h!t creek without a paddle now for sure!

You've got a teenage chickybabe waiting on Val Day and you're asking us Math questions sod the Maths questions champ

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surfbroker said..

Now you know whats on the menu

Oh well, I am two hours drive away from her now, safe and sound.

For those actually helping, I came to an answer. Using the values I got for a and d, these were 102 and -4 respectively. I substituted those into the equation Sn= n/2 (2a+(n-1)d) and got the answer 1280, not sure if correct.

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thePup said..

Teacake said..

surfbroker said..

Teacake said..

surfbroker said..

I think it's 69 !

Explain your working?

Well..it goes like this:
The square of the hypotanous is equal to the sum of the square of the other 2 sides= every action has an equal and opposite reaction=dinner for 2..
That explains it..

Lol, dinner for 2... $h!t! Forgot! The missus text me before and said, What happened to dinner? I am up $h!t creek without a paddle now for sure!

You've got a teenage chickybabe waiting on Val Day and you're asking us Math questions sod the Maths questions champ

An unhappy one now as well! I ditched her for the weekend so I could surf, but have to fit schoolwork in there too

I must be right, the same working is here http://answers.yahoo.com/question/index?qid=20080623151629AAeGl8P, I may have basic mistakes though will check.

you know when you get stuck mate the answer is always 42 ...(hitchhikers guide to the galaxy)

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Teacake said..

surfbroker said..

Now you know whats on the menu

Oh well, I am two hours drive away from her now, safe and sound.

For those actually helping, I came to an answer. Using the values I got for a and d, these were 102 and -4 respectively. I substituted those into the equation Sn= n/2 (2a+(n-1)d) and got the answer 1280, not sure if correct.

Hi Teacake
just saw the thread.
You are bang on the maths...that is formula

Did you use
Xn = a + d(n-1) to establish the 1st and 20th numbers?.....if so you have it

cheers
Climber


Sh1t...I havnt done that stuff since uni

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climber said..

Teacake said..

surfbroker said..

Now you know whats on the menu

Oh well, I am two hours drive away from her now, safe and sound.

For those actually helping, I came to an answer. Using the values I got for a and d, these were 102 and -4 respectively. I substituted those into the equation Sn= n/2 (2a+(n-1)d) and got the answer 1280, not sure if correct.

Hi Teacake
just saw the thread.
You are bang on the maths...that is formula

Did you use
Xn = a + d(n-1) to establish the 1st and 20th numbers?.....if so you have it

cheers
Climber


Sh1t...I havnt done that stuff since uni

yeah used that equation, then just solved simultaneous equations for a and d then just used sum to n formula where n is the term number.

I am 99% sure its all good. This one is a pain but I can do it. Find the sum of all multiples of 8 between 100 and 500.

When the ****k is anyone going to use that shizzz.

Common Teacake lad you don't need that shizz. And to think a young firm teenage chickster was stood for that.

You are coming along Teacake but you still got a long way to go.

ET.

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E T said..

When the ****k is anyone going to use that shizzz.

Common Teacake lad you don't need that shizz. And to think a young firm teenage chickster was stood for that.

You are coming along Teacake but you still got a long way to go.

ET.

Lol, engineering stuff man! My career path!

Not fussed about girls, even if she is my almost 2 year long girlfriend!

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E T said...
When the ****k is anyone going to use that shizzz.


ET.

Only in the Greenroom ET

No fussed about girls!!!

Then the Gold Coast is just the place for you young Teacake.

ET.

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Teacake said..

climber said..

Teacake said..

surfbroker said..

Now you know whats on the menu

Oh well, I am two hours drive away from her now, safe and sound.

For those actually helping, I came to an answer. Using the values I got for a and d, these were 102 and -4 respectively. I substituted those into the equation Sn= n/2 (2a+(n-1)d) and got the answer 1280, not sure if correct.

Hi Teacake
just saw the thread.
You are bang on the maths...that is formula

Did you use
Xn = a + d(n-1) to establish the 1st and 20th numbers?.....if so you have it

cheers
Climber


Sh1t...I havnt done that stuff since uni

yeah used that equation, then just solved simultaneous equations for a and d then just used sum to n formula where n is the term number.

I am 99% sure its all good. This one is a pain but I can do it. Find the sum of all multiples of 8 between 100 and 500.

Teacake I came up with the same equasion as well now go enjoy dinner

Select to expand quote

asea said..

Teacake said..

climber said..

Teacake said..

surfbroker said..

Now you know whats on the menu

Oh well, I am two hours drive away from her now, safe and sound.

For those actually helping, I came to an answer. Using the values I got for a and d, these were 102 and -4 respectively. I substituted those into the equation Sn= n/2 (2a+(n-1)d) and got the answer 1280, not sure if correct.

Hi Teacake
just saw the thread.
You are bang on the maths...that is formula

Did you use
Xn = a + d(n-1) to establish the 1st and 20th numbers?.....if so you have it

cheers
Climber


Sh1t...I havnt done that stuff since uni

yeah used that equation, then just solved simultaneous equations for a and d then just used sum to n formula where n is the term number.

I am 99% sure its all good. This one is a pain but I can do it. Find the sum of all multiples of 8 between 100 and 500.

Teacake I came up with the same equasion as well now go enjoy dinner

Yeh

Select to expand quote

asea said..

Teacake said..

climber said..

Teacake said..

surfbroker said..

Now you know whats on the menu

Oh well, I am two hours drive away from her now, safe and sound.

For those actually helping, I came to an answer. Using the values I got for a and d, these were 102 and -4 respectively. I substituted those into the equation Sn= n/2 (2a+(n-1)d) and got the answer 1280, not sure if correct.

Hi Teacake
just saw the thread.
You are bang on the maths...that is formula

Did you use
Xn = a + d(n-1) to establish the 1st and 20th numbers?.....if so you have it

cheers
Climber


Sh1t...I havnt done that stuff since uni

yeah used that equation, then just solved simultaneous equations for a and d then just used sum to n formula where n is the term number.

I am 99% sure its all good. This one is a pain but I can do it. Find the sum of all multiples of 8 between 100 and 500.

Teacake I came up with the same equasion as well now go enjoy dinner

Can't tell if your serious or not hahaha If you actually are, what did you get for that last question? Sum of multiples of 8...

Not going out for dinner anyway

Teacake that's called cheating I will help you out if you're really stuck now get off this site and go and have a bit of how you going with you're princess

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asea said..

Teacake that's called cheating I will help you out if you're really stuck now get off this site and go and have a bit of how you going with you're princess

Na, she is 200km away now. Thank god, not in the best mood tonight!

Not really stuck, more or less just want to know if I am right haha