Answer:
It would be Choice A, x = 7
Explanation:
So with this, it wants for you to factor out x^2-8x+7.
Since we already have one of the factors, (x-1), this removes most of the work with it. The task is to find the second factor.
With this, the FOIL method is needed. First, Outer, Inner, and Last of each factor are multiplied. Note that the ending numbers of the factor should multiply to give the final number of the standard form. Also, the middle value of the standard form should be the addition of each of the numbers * the x value.
Choice A:
x^2 – 8x + 7
(x-1)(x-7)
Choice A is correct as it follows the rules given above.
Choice B:
x^2 – 8x + 7
(x-1)(x+7)
Choice B is incorrect, because it would be x^2+6x-7 if FOIL is done.
Choice C:
x^2 – 8x + 7
(x-1)(x+8)
Choice C is incorrect, because it would be x^2+7x-8 if FOIL is done.