|1/2009-1/2008|-|1/2008-1/2007| =1/2008-1/2009-1/2007+1/2008 =-1/2009-1/2007 =-4016/4032063
问题描述：
|1/2009-1/2008|-|1/2008-1/2007| =1/2008-1/2009-1/2007+1/2008 =-1/2009-1/2007 =-4016/4032063
答
x:y:z=1:2:3
所以x=y/2=z/3
y=2x,z=3x
所以3x+2y-z
=3x+4x-3x=12
4x=12
所以
x=3,
y=2x=6
z=3x=9
1541153
1035415
答
不对
应该是2/2008-1/2009-1/2007
如果中间是加号,则=1/2009-1/2007=-4016/4032063