If (x – 5) is a factor of f(x), which of the following must be true?

A root of f(x) is x = –5.
B) A root of f(x) is x = 5.
C) Both x = –5 and x = 5 are roots of f(x).
D) Neither x = –5 nor x = 5 is a root of f(x).

Question

If (x – 5) is a factor of f(x), which of the following must be true?

A root of f(x) is x = –5.
B) A root of f(x) is x = 5.
C)  Both x = –5 and x = 5 are roots of f(x).
D)  Neither x = –5 nor x = 5 is a root of f(x).

anonymous · Answer

if$$ f(x)=(x-5)\times \text{something}$$ then 
$$f(5)=(5-5)\times \text{something}$$ i.e. 
$$f(5)=0$$

anonymous · Answer

since $f(5)=0$ we say " a root of $f(x)$ is $5$"

anonymous · Answer

it'd B

anonymous · Answer

@satellite73