Since the highest power of x is 2, u can assume the equation to be (x +/- A) (x +/- B), whereby A and B are unknowns.
Since the coefficient of X^2 is 1, and the number in the equation is - 5, the only possible values for A and B to get - 5 is either - 5 and 1 or 1 and - 5.
Since coefficient of x is - 4 and number in equation is - 5, imagine inserting those numbers in the equation and cross multiplying back. You would realise that the answer should be as listed above.
