Question

for what value of k is 3 a zero of the ploynomial
$2x 2 + x + k$

Answer 1

Heya!
⇒here one of the zero is 3
⇒p(x)=2x²+x+k
Put x=3 in p(x)
⇒2(3)²+(3)+k=0
⇒18+3+k=0
⇒k=-21

Hope this helps you ☺