The 8 factors of 56 are 1, 2, 4, 7, 8, 14, 28, and 56.
2 and 8 add up to 10.
Also, 1, 2, and 7 add up to 10.
-10 & -18
35
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.
The factors of -504 are 2, 2, 2, 3, 3, 7 and -1. Then the factors that add to -3 are -24 and 21.
-8 and +7
7 and -8
56 + 56 + 28 + 8 + 2 + 1 = 151
-57
The factors of 8 are 1, 2, 4, and 8. The factors that add up to 10 are 2 and 8.
1510
-54 and -2 aren't technically factors of 108, but they will satisfy this problem.
-10 and +10.
-49 and -7 -42 and -14 -28 and -28
268
-10 & -18
66
35