Question

The teachers’ editions of a statistics textbook sell for $150 each, and students’ editions of the book sell for $50 each. Which function can be used to find the average cost per book if two teachers’ editions and x students’ editions are purchased?
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Answer 1

Average cost per book = (total cost)/(number of books) = (300 + 50x)/(2 + x).
This simplifies to 50(x + 6)/(x + 2), with x ≥ 0 (and x ≠ −2).