84 =
1 84 = 84
2 42 = 84
3 28 = 84
4 21 = 84
6 14 = 84
7 12 = 84
If the first number was B, and the second number was A, you'd just need to find which two numbers show that A is 5 more than B.
The only pair that do this is 7 and 12, because is if A is 12 and B is 7, you can work out that A = 7 + 5, which is 12, so it works.
A = 12
B = 7
