x+y-z=5,2x+3y+z=10,x-2y-z=20求方程组

(4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? x/2=y/3=z/5 x+3y-z/x-3y+z x+2y+3z=23 y-z=5 x+2z=10 (4x-2y-z)-{5x-[8y-2z-(x+y)]-2(3y-10z)}=?好难啊 已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z 试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) 已知x-y/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuaihuajian X=3z X+y+z=12 X+2y-2z=10 2x+z=10 x+y-z=4 3x-y-z=0 X/10=Y/8=Z/9,则X+Y+Z/2Y-3Z 3x+2y+z=14 ,x+y+z=10,z+2x+3y=1 5 x+y+2z=5 2x-y-z=4 3x+y-3z=10 {2x+3y-4z=-5 x+y+z=6 x-y+3z=10 2x+y-z=3 5x+3y-z=10 求x+y+z= -2X+3Y+Z=-4-X-5Y-2Z=-13X+Y-Z=10 x+y-z=5,2x+3y+z=10,x-2y-z=20求方程组 x+y-z=5 2x+3y+z=10 x-2y-z=20 速解,