If x² + kx + 9 = 0 has equal roots and k is positive, what is k?
Correct answer: B. 6
- A. 3
- B. 6
- C. 9
- D. 12
Explanation
Equal roots require the discriminant to be zero: k² - 4(1)(9) = 0. Thus k² = 36, and because k is positive, k = 6.
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