x-2y=-9,y-z=3,2z+y=47

x+y/2=z+x/3=y+z/4 x+y+z=27 x+2y=3x+2z=4y+z 求x:y:z X/10=Y/8=Z/9,则X+Y+Z/2Y-3Z 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 x+y=5 2x+3y-z=9 x-y+z=4 已知x-y/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. 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 x=y/z=z/3,x+y+z ＝12,求2x+3y+4z是多少, 2x+y-z=2 x-y+2z=2 3x+2y+4z=9 2x+y-z=2 x-y+2z=2 3x+2y+4z=9 解方程组 x+y+z=5 2x-y-z=4 3x-2y-z=9 {x+y+z=0 {4x+2y+z=3 {9x+2y+z=6 {x+y+z=0 4x+2y+z=3 9x+3y+z=6 2x+3y-z=9,x+y+z=15,5x-4y-z=0 x+y+z+2,4x+2y+z+2,9x+3y+z=6解方程组 设|x|-|y|+|z|=|x+y+z|,且|x+y|=4,|y+z|=5,|y|=3,求(x-y-z)^2的值