A+B=252,(1) B+C=197,(2) C+A=149.(3) 由(1)+(2)+(3),得:2A+2B+2C=598 所以:A+B+C=299 (4) 由(4)-(1),得:C=47, 由(4)-(2),得:A=102, 由(4)-(3),得:B=150,