If the sum of the First n term of an Ap is 4n2-3n . find first term and d . Find algebra. is 181 a term of this sequences? Find 25th term

Question

If the sum of the First n term of an Ap is 4n2-3n . find first term and d . Find algebra. is 181 a term of this sequences? Find 25th term

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Kinsley 1 month 2021-08-19T06:32:24+00:00 1 Answer 0 views 0

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    2021-08-19T06:33:45+00:00

    sn=4n^2-3n

    sn-1=4(n-1)^2-3(n-1)

    sn-1=4(n^2-2n+1)-3n+3

    sn-1=4n^2-8n+4-3n+3

    sn-1=4n^2-11n+7

    WE KNOW THAT,

    tn=sn-sn-1

    tn=(4n^2-3n)-(4n^2-11n+7)

    tn=4n^2-3n-4n^2+11n-7

    tn=8n-7

    Therefore the nth term whose sn=4n^2-3n is 8n-7

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