{3x-2y+z-8=0 2x+3y-z-18=0 x+2y=16

已知x-y/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. 证明 ：x/(y+z)+y/(z+x)+z/(x+y)>=3/2其中 x,y,z>0 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+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z 已知x,y,z 大于0,x+y+z=2,求证 xz/y(y+z)+zy/x(x+y)+yx/z(z+x)大于等于2/3 X/10=Y/8=Z/9,则X+Y+Z/2Y-3Z 2x+z=10 x+y-z=4 3x-y-z=0 若|x+3|+|y-2|+|2×z+1|=0求(x×z-y×z)(y-x+z)的值 解三元一次方程：x+y-z=0,2x+y+z=7,x-3y+z=8 三元一次方程x-y+z=6 x+y-z=0 2x+3y+8z=33 解方程组x+y-z=0,2x+y+z=7,x-3y+z=8 已知4x-3y+z=0,x+2y-8z=0,xyz不等于0,求x+y-z/x-y+2z的值 已知:x+y+z=0,5x-3y-z=0,求:5x-y+z/2x+8y+7z 的值 (4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? 如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y, {x+y+z=1;x+3y+7z=-1;z+5y+8z=-2 x/2=y/3=z/5 x+3y-z/x-3y+z x+2y=3x+2z=4y+z 求x:y:z