Advanced Math practice question

Answer: -18

With zeros 1 and 7, f(x) = a(x − 1)(x − 7). Then f(0) = 7a = 14, so a = 2. f(4) = 2(3)(−3) = −18.

Common wrong answers

If you answered 14

14 is f(0).

If you answered 18

18 has the wrong sign: (4 − 1)(4 − 7) = −9.

If you answered -9

−9 forgets the factor a = 2.

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