a+b+c=1800
|----| a
|----|----|----| b
|----|----|----|+50 c
scadem diferenta si avem
1800-50=1750
1750:7=250
a=250
b=3xa=250x3=750
c=b+50=750+50=800
250+750+800=1800(verificare)
B)
C-A=54
C:A=3
C=3xA
3A-A=54
2A=54
A=54:2=27
Adriana are 27 lei
C=3xA=27x3=81
Camelia are 81 lei
81-27=54(verificare)