f(x) = x + 2 g(x) = x – 4(f g)(x) =

Here, (fg)(x) means f(x) multiplied by g(x). Substitute the given expressions: (x + 2)(x − 4) = x² − 4x + 2x − 8 = x² − 2x − 8. So the answer is choice C, x² − 2x − 8.

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