SOLUTION: in a certain ap the 32nd term is twice the 12th term prove that 70th term is twice the 31st term

Question 1019525: in a certain ap the 32nd term is twice the 12th term prove that 70th term is twice the 31st term

Answer by robertb(5830) (Show Source): You can put this solution on YOUR website!
The usual formula for the nth term of an AP is . For the purpose of proving the statement, we use the alternative formula
, where k = 1, 2, 3, ...., n-1.
We are also given that
Using this formula,
,
and the statement is proved.
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