Question

Sn =636,a=9 ,d=8,n=?​

Answer 1

Answer:

sn=n/2(2a(n-1)d)

636=n/2(2*9(n-1)8)

636=n/2(18+8n-8)

636=n/2(10+8n)

636=n/2*2(5+4n)

636=n(5+4n)

636=5n+4n^2

4n^2+5n-636=0

continue the step you will get the answer

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Answer 2

Step-by-step explanation:

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