The 3rd term of an arithinetic progression is-9 and the 7th term is -29. Find the 10th term of the progression.​

Question

The 3rd term of an arithinetic progression is-9
and the 7th term is -29. Find the 10th term of the
progression.​

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Helga 2 weeks 2021-07-22T16:29:13+00:00 1 Answers 2 views 0

Answers ( )

    0
    2021-07-22T16:30:50+00:00

    Answer:

    -64

    Step-by-step explanation:

    The computation of the 10th term of the progression is shown below:

    The 3rd term is -9

    A_n = a + (n – 1)d

    -9 = a + (3 – 1)d

    -9 = a + 2d

    -9 – 2d = a

    Now the 7th term is -29

    A_n = a + (n – 1)d

    -29 = a + (7 – 1)d

    -29 = a + 6d

    Put the a value to the above equation

    -29 = -9 – 2d + 6d

    -29 + 9 = 4d

    -20 = 4d

    d = -5

    Now

    -9 – 2d = a

    -9 – 2(-5) = a

    -9 – 10 = a

    a = -19

    Now finally the 10th term of the progression is

    = a + (n – 1)d

    = -19 + (10- 1)-5

    = -19 -45

    = -64

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Giải phương trình 1 ẩn: x + 2 - 2(x + 1) = -x . Hỏi x = ? ( )