Answer:
C. (x + 8) (x + 7)
Step-by-step explanation:
To factor this trinomial, you must split the middle term (15x) into two terms that can be added to get 15x, and multiplied to get 56:
[tex]x^2 + 15x + 56[/tex]
[tex]x^2 + 7x + 8x + 56[/tex]
Group:
[tex](x^2 + 7x) (8x + 56)[/tex]
Take out the GCF (Greatest Common Factor):
x(x + 7) 8(x + 7)
(x + 8) (x + 7)
