X+Y+Z=20,2X+3Y+8Z=100 那么X Y Z分别是多少,

x=y/z=z/3,x+y+z ＝12,求2x+3y+4z是多少, 试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) (x+y-z)(x-y+z)= x,y,z分别代表三个不同的数,且X+X=x=y+y,y+y+y+y=z+z+z,x+y+y+z=60 ,那么Y+X+Z y=-2X,Z=3y,那么X-Y+(-Z)等于 x/2=y/3=z/5 x+3y-z/x-3y+z {x+y+z=1;x+3y+7z=-1;z+5y+8z=-2 方程组｛2x+5y+3z=0,3x+5y-8z=0.这不等于0,x：z和y：z是多少? 4x-3y-6z=0,x+2y-7z=0是一个方程组,那么x-y+z/x+y+z的值等于 已知x=y/3=z/5.且x+y-2z不等于0.求2x+3y-z/x+y-2z的值是多少 已知方程组4x-y+3z=0 2x+y+6z=0且xyz不等于0,则x/y+y/z+z/x是多少 x-y-z=-1 3x+5y+7z=11 4x-y+2z=-1 分别求出x=?y=?z=?