268
91
I suppose you could use -42 twice. -63 and -21
They add up to 135
2 + 29 + 53 = 84
-76
84
The factors of 21 that add up to 8 are 1 and 7.
72, 81, 90
None. Factors don't add, they multiply.
41 and 43
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.