113
167
The factors of 21 that add up to 8 are 1 and 7.
-113
7 and 1 are two factors of seven. 7+1=8
7 and -8
119
-127
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 7 and 2
5
-13