Question

if one zeri of the quadratic polynomial 2x^{2} - (3k + 1)x - 9
is negative of the other find the vakue of k
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Answer 1

Hey

$f(x) = 2x {}^{2} - (3k + 1)x - 9 \\ \\ let \: one \: zero \: be \: \alpha \\ then \: other \: zero \: would \: be \: - \alpha \\ \\ sum \: of \: zeros \\ \alpha + ( - \alpha ) = - \frac{ - ( 3k + 1)}{2} \\ \\ = > 0 = 3k + 1 \\ \\ = > 3k = - 1 \\ \\ = > k = \frac{ - 1}{3}$
I hope it helps you!!!!