Complete Question:
If (x + k) is a factor of f(x), which of the following must be true?
Correct Answer:
If (x + k) is a factor of f(x), f(-k)=0 must be true
option B
Step-by-step explanation:
We have , (x + k) is a factor of f(x) . For this case we have a function of the form: [tex]f(x)[/tex]. Thus,
x: independent variable
f (x): dependent variable
Since (x + k) is a factor of f (x) then it follows that:
For [tex]f(x)=0[/tex] we have:
⇒ [tex]x+k=0[/tex]
From here, we clear the value of x:
⇒ [tex]x=-k[/tex]
Then, replacing this value of x in the function, we have:
⇒ [tex]f(-k)=0[/tex]
Therefore , Correct option B) f (-k) = 0.