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The value(s) of k for which $x^2 + kx + 9 = 0$ has two equal roots is/are:
A±3
Bonly 6
C±6
D±9
Answer & Solution
Correct answer: C. ±6
Equal roots ⇒ D=0 ⇒ k²−36=0 ⇒ k=±6.
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