If (x + k) is a factor of f(x), which of the following must be true? f(k) = 0 f(–k) = 0 a root of f(x) is x = k. a y intercept of f(x) is x = –k.

The Factor Theorem us that if is a factor of , then .

This means that substituting into the function will leave NO remainder and thus the value would be 0.

From the definition, we clearly see that if is a factor of , then plugging in into will give us a value of 0, or in other words, .

Second option is correct.

ANSWER: must be true.

step-by-step explanation:

what grade level is this? need to know so i can look in my old textbooks!