3x+2y+z=9,x+y+2z=0,2x+3y-z=11

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^2/(z+y)+y^2/(x+z)+z^2/(x+y)=0,求x/(z+y)+y/(x+z)+z/(x+y)的值. x^2/(z+y)+y^2/(x+z)+z^2/(x+y)=0,求x/(z+y)+y/(x+z)+z/(x+y)的值 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 三元一次方程x+y+z=0 4x+2y+z=3 9x+3y+z=6x+y+z=04x+2y+z=3 9x+3y+z=6 解方程 x+y+z=0 4x+2y+z=3 9x-3y+z=28解方程x+y+z=04x+2y+z=39x-3y+z=28 若|x+3|+|y-2|+|2×z+1|=0求(x×z-y×z)(y-x+z)的值 3x+2y+z=9,x+y+2z=0,2x+3y-z=11 {x+y+z=0 {4x+2y+z=3 {9x+2y+z=6 {x+y+z=0 4x+2y+z=3 9x+3y+z=6 已知｛2x-y-z=0,3x-9y+z=0求1,x:y:z 2x+3y-z=9,x+y+z=15,5x-4y-z=0 如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y,