Answer:
A) 5
Step-by-step explanation:
We are given that:
[tex]x^2+kx+6=(x+n)(x+3)[/tex]
Where k and n are constants.
And we want to find the value of k.
We can expand the right-hand side:
[tex]\displaystyle =x(x+n)+3(x+n)\\ \\ = x^2+nx+3x+3n \\ \\ = x^2 + (n+3)x+3n[/tex]
Hence:
[tex]x^2+kx+6=x^2+(n+3)x+3n[/tex]
The coefficients of each term must be equivalent. In other words:
[tex]k=n+3\text{ and } 6=3n[/tex]
Solve for n:
[tex]n=2[/tex]
Now, we can solve for k:
[tex]k=(2)+3=5[/tex]
Our answer is A.
