Math

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20
(Sigma Sign) 2n + 7
k= 1

  • Math -

    ∑2n+7
    =2∑n + ∑ 7
    =2*(20+1)(20/2) + 20*7
    =420+140
    =560

  • Math -

    Thank you, MathMate.

  • Math -

    Wait, do you know how it could be plugged into the Sn= a1 (1 - r^n/ 1 - r) formula?

  • Math -

    Sn= a1 (1 - r^n/ 1 - r)
    applies when the series is a geometric progression, such as

    20
    ∑ a1*r^i
    i=1

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