the sum of first 9 terms of an AP is 81 and the sum of its first 20 terms is 400. find the first term and the common difference of the AP
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Answered by
42
Easy, bro
Make two equestion
Sum nth term =n/2{2a+(n-1)d
So equet both equation 1)and(2)
Then value Should be find
Much easy bro,
Make two equestion
Sum nth term =n/2{2a+(n-1)d
So equet both equation 1)and(2)
Then value Should be find
Much easy bro,
Answered by
103
this is the answer.hope it helps
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