Question

12. If 3 is a zero of the polynomial 2x² + x + k, then k =........​

Answer 1

Answer is -21.

A zero of the polynomial satisfies the equation when it is substituted in the place of variable.

This is also can be said as root of polynomial.

Given polynomial 2x^2+x+k=0

Given, 3 is a zero of polynomial.

So when x is substituted with 3 the equation should be held.

2(3^2)+3+k=0

2(9)+3+k=0

18+3+k=0

21+k=0

k=-21.

Hope you're satisfied with this solution.