OpenStax, Algebra and Trigonometry 2e §13.2 Arithmetic Sequences · Exercise 25 · Probability · Counting & chance

Arithmetic Sequences · Exercise 25

Find the first term given two terms from an arithmetic sequence.

Find the first term or $a_{1}$ of an arithmetic sequence if $a_{7} = 21$ and $a_{15} = 42.$

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OpenStax, Algebra and Trigonometry 2e · §13.2 Arithmetic Sequences · Exercise 25

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