1) a+b+c=654
b:a=11 rest 10
c:a=25rest15
c=a*25+15
b=a*11+10
a+(11a+10)+(25a+15)=654
a+11a+25a=654-10-25
37a=629 deci a=17
b=17*11+10 deci b=187+10=197
c=17*25+15 deci c=425+15=440
proba 17+197+440=654
2) a+b=120 si b+c=230
a+2b+c= (a+b)+(b+c)=120+230=350
5a+8b+3c=5(a+b)+3(b+c)=5*120+3*230=600+691290