if the first term of an A.P is 2 and common difference is 4 then the sum of its first 40 terms is?​

Question

if the first term of an A.P is 2 and common difference is 4 then the sum of its first 40 terms is?​

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Maya 2 months 2021-08-14T01:26:21+00:00 2 Answers 0 views 0

Answers ( )

    0
    2021-08-14T01:28:09+00:00

    Answer:

    a=2

    d=4

    n=40

    Sn=?

    Sn=n/2×{2a+(n-1) d}

    Sn= 40/2 ×{2×2+39×4}

    Sn=20×160

    Sn=320

    therefore sum of 40 terms is 320

    0
    2021-08-14T01:28:17+00:00

    Answer:

    Sn = n [2a+ (n-1)d]

    2

    n= 40 ; a= 2 ; d = 4

    S40 = 40 [2×2 + ( 40 – 1) ×4 ]

    2

    = 20 [ 4 + ( 39× 4) ]

    = 20 [ 4 + 156]

    = 20 × 160

    = 3200 ANS.

    MARK ME AS BRAINLIEST ....

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