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Given h(x) = x-3 and f(x) = x3-x2-x-15 is h(x) a factor of f(x)?

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Answer:

Yes.

Explanation:

To see if h is a factor of f, we can use the factor theorem.

h(x)=x-3 has a zero at x=3 because h(3)=3-3=0.

So we want to see if the zero of h is a zero of f.

Is x=3 a zero of f?

You can check using synthetic division or just plug in 3.

Let's do both.

If you use synthetic you are trying to see if you get a remainder of 0.

If you plug it in you are trying to see if you get 0 as the output when plugging your input 3.

Let's do synthetic first:

Since we are checking to see if x=3 is a zero, that will go on the outside:

3 | 1 -1 -1 -15

| 3 6 15

- ------------------------

1 2 5 0

So yep the remainder is 0 so the answer is yes.

Let's plug it in:

f(3)=3^3-3^2-3-15

f(3)=27-9-3-15

f(3)=18-3-15

f(3)=15-15

f(3)=0

The result is 0 so the answer is yes.

You pick your favorite way here.

User Michael Richards
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