Subtract the difference and half your answer, giving 9 which is the smaller number, add the difference to this and you get 38 which is the larger number.
67 and 99
6 & 4
29 and 36
37 and 21
The answer is: 3
67 and 99
29 and 36
22 and 26
6 & 4
37 and 21
19 and 34
12 and 24?
20 & 3
18 and -6.
28 and 36
The answer is: 3
12 and 15 have a sum of 27 and a difference of 3. Their LCM is 60.