Answer:
Correct choice is B
Step-by-step explanation:
Start with the quadratic trinomial [tex]x^2-x-56.[/tex] First, find the discriminant:
[tex]D=(-1)^2-4\cdot 1\cdot (-56)=1+224=225=15^2.[/tex]
Then the roots are
[tex]x_{1,2}=\dfrac{-(-1)\pm15}{2\cdot 1}=\dfrac{1\pm 15}{2}=-7,\ 8.[/tex]
The factored form of the quadratic trinomial is [tex](x-x_1)(x_x_2)=(x-(-7))(x-8)=(x+7)(x-8)[/tex]
and the factors of -56 are -7 and 8.
