14)405+345+126=876 ramasi bani in total
975-876=99 lei au cheltuit cei trei copii
99:3=33 lei au costat jucariile de copil
405+33=438 lei 1 copil
345+33=378 lei 2 copil
126+33=159 lei 3 copil
Verificare
438+378+159=975 lei
15)a-baloane verzi
B-baloane rosii
C-galbene
A+b+c=900
A=3b
A=c-25
C=25+a
C=25+3b
3b+b+25+3b=900
7b=900-25
B=875:7
B=125 baloane rosii
A=3x125
A=375 baloane verzi
C=25+375
C=400 baloane galbene
Verificare
375+125+400=900
500+400=900
900=900