Question

for what value k is 4 a zero of f(x)=x^2+kx+4 ?

Answer 1

Answer:

4 is the zero of the polynomial;

so, X=4

x(4)=(4)2+4k+4=0

x(4)=16+4k+4=0

x(4)=20+4k=0

x(4)=k=-20/4

k=-5

hope this will help you

Answer 2

Concept :

The expression of more than two algebraic terms, and the sum of several terms that contain different powers of the same variables.

Given :

We have given a polynomial $f(x)=x^2+kx+4$.

Solution :

Now,

$4$ is the zero of the polynomial;

so, $X=4$

$f(x)=x^2+kx+4\\4^2+k4+4=0\\20+4k=0\\k=\frac{-20}{4} \\k=-5$

Hence, the correct answer is $-5$.

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