Răspuns :
a-b=28
a/b=5
a=b*5
5*b-b=28
5b-b=28
4b=28
b=28/4
b=7
a=7*5
a=35
verificare 35-7=28
a/b=5
a=b*5
5*b-b=28
5b-b=28
4b=28
b=28/4
b=7
a=7*5
a=35
verificare 35-7=28