The variables A, B, and C represent polynomials where A = x + 1, B = x2 + 2x − 1, and C = 2x. What is AB + C in simplest form?

Substitute the polynomials into AB + C: (x + 1)(x² + 2x − 1) + 2x. Distributing gives x³ + 3x² + x − 1, and adding 2x gives x³ + 3x² + 3x − 1. This matches choice C.

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