a-b+a-b = b+b-c = c+c-a+b
2a-2b = 2b-c = 2c-a+b
2a-2b = 2b-c
2a+c= 2b+2b
2a+c=4b
c=4b-2a
2b-c = 2c-a+b
2b-b = 2c-a+c
b=3c-a
c=4(3c-a)-2a=12c-4a-2a
6a=11c
a+b+c=48
a+3c-a+c=48
4c=48
c=48:4
c=12
6a=11*12
a=11*12:6=22
a=22
b=3*12-22=36-22=14
b=14
prima cutie = 22 , a doua cutie=14, a treia cutie = 12