The factors of -84 that equal the sum of -16 are:
-28 and 12
-14 and -2
-12 and -4
11, 22, 36 and 84
84 is one of 16 factors of 168.
The sum of 84 and 72 is 156.
21 and 1 are factors of 84.
101
There are no such numbers. The only two numbers that sum to 12 and whose product is -84 are irrational, and so cannot be considered as factors of 84.
84
7 and 12
The sum is 144 if 60 is included, 84 if not.
The prime factors of 84 are 2x2x3x7.
-84
11, 22, 36 and 84