What is the first term?

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The sum of the first 10 terms of an arithmetic sequence is 120, and the common difference between consecutive terms is 5. What is the first term of the sequence?

Comments

  1. Rithvik14 August 2023 at 10:16

    For this we can set up an equation:

    x + x + 5 + x + 10 + x + 15 + x + 20 + x + 25 + x + 30 + x + 35 + x + 40 + x + 45 = 120
    10x + 225 = 120
    10x = -105
    x = -10.5

    Therefore, the first term of the sequence is -10.5

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