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Challenging Math, anyone?
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Crystal876
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Joined: 05/04/2015 - 09:13
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Challenging Math, anyone?

The sum of the first 100 terms of an arthmetic progresion is 15050.The first,third and eleventh terms of this progression are 3 consecutive terms of a geometric progression.Find the first term, and common difference of the arithmetic progression.

chanviokins
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Joined: 12/04/2015 - 18:49
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maths

yhheartkiss

 

silas chester ombui
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Joined: 14/04/2015 - 12:18
Posts: 1
how to work it out

sum of n terms of an AP=n/2[2a+(n-1)d]

1st a

3rd a+2d

11th a+10d

a+2d/a=a+10d/a+2d

6a-4d=0......... eqt 1

2a+99d=1505......eqt 2

a simulteneuos equation

solve.

try that.

 

 

kacia
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Joined: 20/01/2017 - 01:42
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math

yessss me , i need help!!