Question

for what value of K ,3 is a zero of polynomial 2x square + x + k?

Answer 1

2 (3)+3+k=0
6+3+k=0
9+k=0
k=-9

Answer 2

On putting x = 3 on the given polynomial we get 2 × 3 ×3 + 3 + k = 0
i. e., 18 + 3 +k = 0
i.e., 21 + k = 0
i.e., k = -21