Răspuns :
a+b+c=2 013
b=2xa+5
b=c-3, rezulta ca c=b+3=2a+5+3=2a+8
a+2a+5+2a+8=2 013
5a=2 013-8-5
5a=2 000
a=2000:5
a=400
b=2a+5=2x400+5=805
c=805+3=808
Verific: 400+805+808=2013
b=2xa+5
b=c-3, rezulta ca c=b+3=2a+5+3=2a+8
a+2a+5+2a+8=2 013
5a=2 013-8-5
5a=2 000
a=2000:5
a=400
b=2a+5=2x400+5=805
c=805+3=808
Verific: 400+805+808=2013
a+b+c=2 013
b=2xa+5
b=c-3, rezulta ca c=b+3=2a+5+3=2a+8
b+2*b+5+2*b+8=2 013
5*b=2 013-8-5
5*b=2 000
b=2000:5
b=400
a=2b+5=2x400+5=805
c=805+3=808
Verific: 400+805+808=2013
b=2xa+5
b=c-3, rezulta ca c=b+3=2a+5+3=2a+8
b+2*b+5+2*b+8=2 013
5*b=2 013-8-5
5*b=2 000
b=2000:5
b=400
a=2b+5=2x400+5=805
c=805+3=808
Verific: 400+805+808=2013