设(x+y)/2=(x+z)/3=(y+z)/4=k则x+y=2k x+z=3k y+z=4k 代入x+y+z=272k+3k+4k=27 k=3所以 x+y= 6 (1)x+z=9 (2)y+z=12 (3)(1)+(2)+(3) 2(x+y+z)=27 x+y+z=27/2 (4)(4)-(1) z=15/2(4)-(2) y=9/2(4)-(3) x=3/2即为所求...