Question

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

Answer 1

Answer:

A root of f(x) is x=5

Step-by-step explanation:

If (x-5) is a factor of f(x), then 5 is a root.

If (x+5) is a factor of f(x), then -5 is a root.

So we are only given that (x-5) is a factor of f(x), so we only know that x=5 is a root.

This is by factor theorem. It says if (x-c) is a factor then f(c)=0 which means c is a root of f(x) because it makes the expressions equal to 0.

Answer 2

The second choice is true.