-10, 4.
26
6 and -1
15
How about 3 and 6
6 and 9
60
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.
23
146
9 and -3
They are 8 and 6
-1, 6 and -12.