Question

For what value of $k$, is $-2$ a zero of the polynomial $2x^2+x+k$.

• A. $-6$
• B. $14$
• C. $-33$
• D. $11$

Answer 1

The correct option is A $-6$

If $-2$ is a zero of the polynomial $p\left(x\right)=2x^2+x+k$ then $p(-2)=0$.

Now substitute $x=-2$ in the polynomial $p\left(x\right)=2x^2+x+k$ and equate it to $0$ as shown below:

$p(-2)=2(-2{)}^2-2+k\Rightarrow 0=(2\times 4)-2+k\Rightarrow 0=8-2+k\Rightarrow 0=6+k\Rightarrow k=-6$

Hence, $k=-6$.