{2x+3y+4z=16,3x-2y+5z=8,5x-6y+7z=4 急用!

(4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? 1.{x:y:z=3:4:5 2x+3y-5z=-142.{x-y-z=-1 3x+5y+7z=11 4x-y+2z=-13.{x+y=1 x+z=0 2x+y+2z=44.{x-y+z=-3 2x-y-z=-2 -3x+y+z=-15.{x-y+z=-3 3x+y-4z=6 2x+y-z=36.{x-2y+5z=16 2x+y-5z=7 2x-y+z=38 (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuaihuajian 设|x|-|y|+|z|=|x+y+z|,且|x+y|=4,|y+z|=5,|y|=3,求(x-y-z)^2的值 x+y=5 2x+3y-z=9 x-y+z=4 (4x-2y-z)-{5x-[8y-2z-(x+y)]-2(3y-10z)}=?好难啊 x/2=y/3=z/5 x+3y-z/x-3y+z x+2y=3x+2z=4y+z 求x:y:z x+y/2=z+x/3=y+z/4 x+y+z=27 x/2=y/4=z/5 3x+4y+2z=16 已知x-y/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. x:y=3:2 y:z=5:4 x+y+z=66 x:y=3:2 y:z=5:4 x+y+z=66 {x:y=2:3 y:z=4:5 x+y+z=35 x:y=2:3 y:z=4:5 x+y+z=35 x+y+z=111,y:x=3:2,y:z=5:4 3x=4y 2y=5z 试求x:y:z 已知：4x-5y+2z=0 x+4y-3z=0则：(x*x+y*y+z*z)/(x*y+y*z+z*x)=____.