Question

For what value of k is 3 a zero of the polynomial 2x2+x+k

Answer 1

Answer:k = -21

Step-by-step explanation:

It is given that 3 is a zero of the polynomial, therefore 3 can make the whole polynomial equal to zero.

So, p(3) = 0

p(x) = 2x^2 + x + k

p(3) = 2(3)^2 + 3 + k

0 = 2 × 3 × 3 + 3 + k

0 = 18 + 3 + k

0 = 21 + k

-21= k

k = -21