r(x) = –x² + 3x s(x) = 2x + 1(s – r)(x) =

To find (s − r)(x), subtract r(x) from s(x): (2x + 1) − (−x² + 3x). This matches choice C. Simplifying gives x² − x + 1; the parentheses are important because subtracting r changes the signs of both its terms.

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