How do you factor #x^2 +6x+40#?
The factored is in the form y = (x - p)(x -q).
Find p and q knowing their sum b = 4 and their product c = 40.
Compose factor pairs of c = 40. Proceed: (1, 40)(2, 20)(4, 10)(5, 8).
We can't find the pair whose sum is 6. Then, this equation can't be factored.
Find D = b^2 - 4ac = 36 - 160 < 0. There are no real roots, then, this equation can't be factored.