Making a difference:
2,5,7,8
57-28=29 58-27=31 72-58=14 75-28=47 78-25=53 78-52=26
57 58 72 75 78 78
-28 -27 -58 -28 -25 -52
29 31 14 47 53 26
87-52=35 87-25=62 85-72=13 85-27=58 82-75=7 82-57=25
87 87 85 85 82 82
-52 -25 -72 -27 -75 -57
35 62 13 58 07 25
In order to find the solution to this problem,I worked systematically.First of all I worked out all the possible sums if your first digit of the bigger number was five;then I did the same with seven,then eight.I didn't try it with two because,all the other numbers possible would be bigger than any possible with the number two and then you would get a negative number,which wouldn't work.