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 October 28th, 2016, 10:34 AM #1 Newbie   Joined: Oct 2016 From: Minna Posts: 8 Thanks: 0 Arithmetic Progression (AP) Given that the 8th term of an AP is 5 times the 3rd term and the 7th term is 9 greater than the 4th term, find the first five terms.
October 28th, 2016, 10:48 AM   #2
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Quote:
 Originally Posted by Hezekiah Given that the 8th term of an AP is 5 times the 3rd term and the 7th term is 9 greater than the 4th term, find the first five terms.
$a_n = a_1 + (n-1) d$

$a_8 = 5 a_3$

$a_7 + 9 = a_4$

plug in expressions for $a_n$ above and solve for $a_1$ and $d$

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