Multiple choice

The quadratic function f is defined as f(x) = kx2 – 5x, where k is a constant. If f(2) = 2, what is the value of f(3)?

  1. 10

  2. 12

  3. 15

  4. 27
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Given f(x) = kx^2 - 5x and f(2) = 2, we have k(2^2) - 5(2) = 2, so 4k - 10 = 2, 4k = 12, k = 3. Then f(3) = 3(3^2) - 5(3) = 27 - 15 = 12.

AI explanation

Substitute 2 for x in the function f(x) = kx^2 - 5x to establish the equation 4k - 10 = 2. Solving this linear equation gives 4k = 12 and k = 3. The function becomes f(x) = 3x^2 - 5x, so substituting 3 for x results in f(3) = 3(3)^2 - 5(3) = 27 - 15 = 12.

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