Which statement best describes how to determine whether f(x) = x3 + 5x + 1 is an even function?

To determine whether a function is even, check whether f(−x) is equal to f(x). Substituting −x into the function gives (−x)³ + 5(−x) + 1, which should be compared with x³ + 5x + 1. This is the test described by choice B.

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