26
34
146
204
6 and -1
what two factors of -21 add up to -6
2, 4, 6, 10, 12, 20, 30, 60 add up to 144.
15
6 and 9
How about 3 and 6
60
23
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.