Răspuns :
a+b+c=9878
b=4a
c=b: 2+15
a+4a+2a+15=9878
7a=9863
a=1409
b=1409*4
b=5636
c=1409*2+15
c=2833
b=4a
c=b: 2+15
a+4a+2a+15=9878
7a=9863
a=1409
b=1409*4
b=5636
c=1409*2+15
c=2833
Notam cele 3 necunoscute cu a,b si c
a+b+c=9878
a=b/4
c=b/2+15
b/4+b+b/2+15=9878
b+4b+2b+60=9878*4
7b=9878*4--60
7b=39452
b=5636
a=1409
1409+5636+c=9878
c=2833
a+b+c=9878
a=b/4
c=b/2+15
b/4+b+b/2+15=9878
b+4b+2b+60=9878*4
7b=9878*4--60
7b=39452
b=5636
a=1409
1409+5636+c=9878
c=2833