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Math Help - Algebra help :( arithmetics

  1. #1
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    Algebra help :( arithmetics

    Insert 3 arithmetic means between -27 and 127.
    Use a formula and show your work.

    -27, _____, _____, _____, 127
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  2. #2
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    Hello, Steph07!

    Insert 3 arithmetic means between -27 and 127: . \text{-}27\;\;\_\_\;\;\_\_\;\;\_\_\;\;127

    This is an arithmetic sequence: .first term a_1 = -27, number of terms  n = 5
    And we must find the common difference d.

    We know that: . a_n \:=\:a_1 + (n-1)d\:\text{ and }\;a_5 = 127

    So we have: . 127 \:=\:-27 + 4d \quad\Rightarrow\quad d = 38.5


    The five terms are: . \text{-}27\quad{\color{blue}11.5\quad50\quad88.5}\quad 127

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