Question

Factor the trinomial: x2 - x - 56
(x + 1)(x - 56)
(x + 7)(x - 8)
(x - 1)(x - 56)
(x - 7)(x + 8)

Answer 1

hello : 
x² -x -56 = (x + 7)(x - 8)
because : (x + 7)(x - 8) = x² - 8x +7x - 56
                                      = x² -x -56