Question

Which model shows the correct factorization of x2 + 2x - 8

Answer 1

The correct answer is D.

I just took the test.

Answer 2

To factor x^2 + 2x - 8 follow these steps

1) Write to factors, with x as the first term, this way:
(x      )(x      )

2) The sign to the right of the x in the first factor is the same sign of the coeficient of x in the polynomial.
That is +.

The sign to the right of the x of the second factor is the product of the sign of the coefficent of x (this is +) and the sign of the independent term (this is - ).
So that is (+).(-) + -.
Now the two factors have this form:
(x +  ) (x  -  )

3) Now find two numbers whose product is - 8 and whose difference is +2

Those numbers are + 4 and -2.

Then the two factors are:
(x + 4) (x -  2).

So the answer if that the correct factorization is (x + 4) (x - 2)