Find the sum of the arithmetic series given a1 12, d = 4, and n = 30. A. 8434 B. 4200 C.4216 D. 2100

Question

Find the sum of the arithmetic series given a1
12, d = 4, and n = 30.
A. 8434
B. 4200
C.4216
D. 2100

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Thiên Ân 3 years 2021-07-25T13:23:50+00:00 2 Answers 54 views 0

Answers ( )

  1. Calantha
    0
    2021-07-25T13:25:06+00:00
    Reply

    It’s B trust me I know

  2. thienthi
    0
    2021-07-25T13:25:25+00:00
    Reply

    Answer:

    D

    Step-by-step explanation:

    The sum to n terms of an arithmetic series is

    S_{n} = \frac{n}{2} [ 2a₁ + (n – 1)d ]

    where a₁ is the first term and d the common difference

    Here a₁ = 12, d = 4 and n = 30 , then

    S_{30} = \frac{30}{2} [ (2 × 12) + (29 × 4) ]

         = 15(24 + 116)

         = 15 × 140

         = 2100 → D

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