Question

if 5 is one of the zeros of the polynomial P(x)=2x^+kx-4 then k=

Answer 1

Hi MATE

Here is your answer

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Let the first zero be x then the another one is 1/x

now, alpha × beta = c/a

x × 1/x = 3k/k+4

1= 3k/k+4

k+4=3k

4=2k

therefore, k=2

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Hope it helps you

Answer 2

SOLUTION

$p(5) = 2 {(5)}^{2} + k(5) - 4 = 0 \\ = > p(5) = 2 \times 25 + 5k - 4 = 0 \\ = > p(5) = 50 + 5k - 4 = 0 \\ = > p(5) = 46 + 5k = 0 \\ = > p(5) = 5k = - 46 \\ = > p(5) = k = - \frac{46}{5}$

hope it helps ☺️