Question

5. For what value of k , if 3 is a zero of
polynomial . 2x² + x +k?​

Answer 1

Answer:

Hello mate,

$2x{^2}+x+k=0$

$2(3) {^2}+3+k=0$

$2×9+3+k=0$

$18+3+k=0$

$21+k=0$

$k=-21$

Answer 2

Hey mate!!

Here's your answer...

The polynomial is :

2x² + x + k

 3 is zero of polynomial for some value of k, then

2x² + x + k = 0

2(3)² + 3 + k = 0           (Putting x = 3)

2*9 + 3 + k = 0

18 + 3 + k = 0

21 + k = 0

k = -21

Therefore,

k = -21, 3 is a zero of the polynomial.

Hope it helped you....