268
23
Factors of 250 that add up to 8 = 1 + 2 + 5
212
1012
35
31
15 and 4 are the factors of 120 that add up to 19.
The factors of 35 are 1, 5, 7 and 35. None of them add up to -5.
Factors are multiplied, not added. The question needs to be something like, "Which two factors of thirty add up to 11?" The answer would then be 5 and 6.
335
8 and 5