Question

What are the factors of –56 that would be relevant in the correct factorization of?

Answer 1

-8, 7

Explanation:

We need factors of -56 that add together to give -1

What two numbers multiply together to give -56 and add to -1

-8 *7 = -56

-8+7 = -1

(x-8) (x+7)

Answer 2

Correct choice is B

Explanation:

Start with the quadratic trinomial
`x^2-x-56.` First, find the discriminant:

`D=(-1)^2-4\cdot 1\cdot (-56)=1+224=225=15^2.`

Then the roots are

`x_(1,2)=(-(-1)\pm15)/(2\cdot 1)=(1\pm 15)/(2)=-7,\ 8.`

The factored form of the quadratic trinomial is
`(x-x_1)(x_x_2)=(x-(-7))(x-8)=(x+7)(x-8)`

and the factors of -56 are -7 and 8.