Question

For what value of k,is 3 a zero of polynomial $2x^{2}+x+k?$

Answer 1

SOLUTION :  

Let p(x) = 2x² + x + k

Since, x = 3 is a zero of polynomial p(x).

Therefore, p(3) = 0

p(x) = 2x² + x + k

2(3)² + 3 + k = 0

2 × 9 + 3 + k = 0

18 + 3 + k = 0

21 + k = 0

k = 0 -21

k = -21

Hence, the value of k is -21.

HOPE THIS ANSWER WILL HELP YOU..

Answer 2

hey mate here is ur solution.....
given:- x = 3
therefore substitute the value of x in p(x)
i.e.p(x)= 2x^2+ x +k =0
therefore 2(3)^2 + (3) + k
=> 18+3+k =0
21+k =0
k = -21 ans...