If one root of the quadratic equation x^2 + 3x + k = 0 is twice the other root, what is the value of

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A. -3

B. -4

C. -2

D. -1

E. None of the above

Answer: B. -4

Let the roots be r and 2r. Then, r + 2r = -3 (sum of roots) gives 3r = -3, so r = -1. The product of the roots is r * 2r = -1 * -2 = 2. Thus, k = 2.

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