Advanced Math practice question

Answer: 5

Factor out 5 first: 5(x² − 4) = 5(x − 2)(x + 2), so k = 5.

Common wrong answers

If you answered 4

4 is x²'s companion inside the parentheses (x² − 4), not the multiplier.

If you answered 10

Check by expanding: 10(x − 2)(x + 2) = 10x² − 40, twice too large.

If you answered 20

20 is the constant term of the original; the common factor is 5.

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