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.
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.
They are 1 and 2
35
15 and 4 are the factors of 120 that add up to 19.
26
-1, 6 and -12.
Factors multiply. The same set of numbers won't add up to both 140 and 240, but 120 and 20 are factors of 240 that total 140.
262
113
149
-10 and 2 -12 and 4 -20 and 12
341
134
-102
Although negative numbers aren't usually considered factors, you can use -21, -3 and -2.