Question

X² +5x +6=0

Answer 1

in some cases, yes.

If you want to factor it, which two factors of 6 add up to 5?

Answer 2

X^2 + 5x + 6 = 0; factorize
X^2 + 2x + 3x + 6 = 0.
X (x + 2) + 3(x + 2)= 0.
(X + 2) + (x + 3) = 0.
X + 2 = 0, x + 3 = 0.
Collect like terms.
X = -2, x = -3.
therefore, x = -2 or -3