Advanced Math practice question

Answer: 5

n² = 2n − 4 + 19 gives n² − 2n − 15 = (n − 5)(n + 3) = 0, so n = 5.

Common wrong answers

If you answered 3

3 gives 9 against 2(3) + 15 = 21.

If you answered 19

19 copies a constant.

If you answered -3

−3 is the negative root.

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