设甲是x,乙是y,丙是z则x+y+z=35(1)2x-5=y(2)y/3=z/2所以z=2y/3(3)(3)代入(2)z=2y/3=2(2x-5)/3=(4x-10)/3(4)(2),(4)代入(1)x+(2x-5)+(4x-10)/3=353x+6x-15+4x-10=10513x=130x=10y=2x-5=15z=2y/3=10答：甲是10,乙是15,丙是10
