C+M =160
M+I=134 rezulta ca M = 160-C
C+ I=146 REZULTA CA I= 146-C
____________
2C+2M+2I=160+134+146
2(C+M+I)= 440
C+M+I=440:2
C+M+I=220
inlocuim si avem:
C+160-C+146-C=220
160+146-220=C+C-C
86=2C-c
86=C,
acum inlocuim si avem:
C+M= 160, 86+M = 160, M = 160-86, M = 74
M+I=134, 74+I=134, I= 134-74, I = 60