-19
Well, 18 and 3 (both factors of 36) add up to 21. As well, the factors 12 and 9 add up to 21.
119
They are: 21+6+2 = 29
3551
Although negative numbers aren't usually considered factors, you can use -21, -3 and -2.
To find factors of -504 that add up to -3, we must consider both positive and negative factors. The factors of 504 are 1, 2, 3, 4, 6, 7, 8, 9, 12, 14, 18, 21, 24, 28, 36, 42, 56, 63, 72, 84, 126, 168, 252, and 504. By considering the negative factors as well, we can identify that -7 and -72 are factors of -504 that add up to -3.
The factors of 8 are 1, 2, 4, and 8. The factors that add up to 10 are 2 and 8.
31
factors of 30 that add to 17 are 2 and 15
167
-1005
-261