Question

Which of the following is NOT a factor of x3 + x2 - 4x - 4?x + 1x + 2x - 1x - 2

Answer 1

Answer: (x - 1)

Step-by-step explanation

Given:

`x^3+x^2-4x-4`

To factor a third-degree polynomial, we can do it by grouping:

`=(x^3+x^2)+(-4x-4)`

Then, we have to find the common factor between groups:

`=x^2(x+1)-4(x+1)`

Now, we can get the common factor of (x+1):

`=(x^2-4)(x+1)`

Finally, the differences of squares equal the following:

`(x^2-a^2)=(x-a)(x+a)`

Then, applying this rule to our factor we get:

`=(x+2)(x-2)(x+1)`

Thus, the only factor that is not correct is (x - 1)