For which values of k does x² + (k − 3)x + k = 0 have equal roots?
Correct answer: C. k = 1 or 9
- A. k = 1 only
- B. k = 9 only
- C. k = 1 or 9
- D. k = −1 or −9
Explanation
Equal roots require the discriminant to be zero. Here, (k − 3)² − 4k = k² − 10k + 9 = (k − 1)(k − 9), giving k = 1 or k = 9.
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