Math, asked by Anonymous, 1 year ago

Which term of the AP :129,125,121.......... is its frst negative term

Plz give justification

Answers

Answered by nlavanya
2
a=129, d=125-129=-4, let an=0

an=a+(n-1)d
0=129+(n-1)(-4)
-129=-4n+4
-125=-4n
-125/-4=n
n=-31.25
since n has to be a whole no., therefore, the ans is 32 ( the no. next to 31.25)

hence the 32nd term is the first negative term



Anonymous: Hai its wrong
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