2x+3y=5 3y-4z=3 4z+5x=7

(4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? 设|x|-|y|+|z|=|x+y+z|,且|x+y|=4,|y+z|=5,|y|=3,求(x-y-z)^2的值 (4x-2y-z)-{5x-[8y-2z-(x+y)]-2(3y-10z)}=?好难啊 (x+y):(y+z):(z+x)=3:4:5 3x+y-z=-4已知(x+y):(y+z):(z+x)=3:4:5 ；3x+y-z=-4求x y z x+y=5 2x+3y-z=9 x-y+z=4 若xyz≠0且4(x/z)-5(y/z)=-2,(x/z)+4(y/z)=3,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)=____. 3x-2y+z=4 x+y-z=5 4x-4y+3z=27 ｛ 5x-3y+z=25x+2y-4z=3-5x+y-z=2 x+y+z=4 2x-y+z=3 3x-2y-3z=-5 已知(x+2y)/3=(y+3z)/4=(z+5x)/5,则x:y:z= 已知x+2y/3=y+3z/4=z+5x/5,则x:y:z=? 已知x+2y/3=y+3z/4=z+5x/5,则x:y:z= x:y:z=3:4:5 2x-3y+2z=8 x-y-2z=? x+y+z=4,x+2y-z=4,3x-y+4z=5 x+y+z=-5,3x+y+z=1,4x+3y+2z=-2快 若x/2=y/3=z/4,则3x-2y+5z/x+y+z= x+y+2z=5 2x-y-z=4 3x+y-3z=10