Answer:
6
Step-by-step explanation:
We want to factor the trinomial into a product of binomials. In general, we have ...
(x +a)(x +b) = x² +(a+b)x +ab
So, the values of "a" and "b" need to have a product of 12. There are 6 ways to do that:
12 = 1·12 = 2·6 = 3·4 = (-1)(-12) = (-2)(-6) = (-3)(-4)
The values of k are the sums of these factors of 12, so are
1+12 = 13
2+6 = 8
3+4 = 7
-1-12 = -13
-2-6 = -8
-3-4 = -7
There are 6 possible integer values of k that will make the trinomial factorable in integers:
k ∈ {-13, -8, -7, 7, 8, 13}
