24)a+b+c=183997
b=3*a/3+1999
c=2a+1998
a+3a/3+1999+2a+1998=183997
3a+3a/3=183997-3997
9a/3+3a/3=180000
12a/3=180000
4a=180000
a=180000:4
a=45000
b=3a/3+1999=3*45000/3+1999=45000+1999=46999
b=46999
c=2a+1998=2*45000+1998=90000+1998=91998
c=91998
25)a-b=399750
b=a/6
a-a/6=399750
6a/6-a/6=399750
5a/6=399750
a=399750*6:5=2398500:5=479700
a=479700
b=479700/6=79950
b=79950
23) a+b=422000
b=3a/2+172000
a+3a/2+172000=422000
2a/2+3a/2=422000-172000
5a/2=250000
a=250000*2:5=500000:5=100000
a=100000
b=3*100000+172000=300000+172000=472000
b=472000