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Problem 14 - Entrance Test

If f(x + 1) = x^2 + 3x + 2, what is f(x)?

Correct: B

Let y = x + 1, so x = y - 1. Then f(y) = (y - 1)^2 + 3(y - 1) + 2 = y^2 - 2y + 1 + 3y - 3 + 2 = y^2 + y. Therefore, f(x) = x^2 + x.