已知3x-4y-z=0.2x+y-z=0,且xyz=0,求x+2y-3z/3x-2y+3z3x-4y-z=零点二x+y-z=0

已知x+y+z=0求证x*x*x+y*y*y+z*z*z=3xyz 已知 x-3y+z=0 3x-3y-4z=0,则x:y:z=已知x-3y+z=0 3x-3y-4z=0则x:y:z= 已知3x-4y-z=0.2x+y-z=0,且xyz=0,求x+2y-3z/3x-2y+3z3x-4y-z=零点二x+y-z=0 已知4x-3y+z=0,x+3y-3z=0,则x:y:z=( ) 已知x-2y+3z=0,x-3y+4z=0,则x:y:z= 已知{x-3y+2z=0 3x-3y-4z+0,则x:y:z=? 已知4x-3y-3z=0 x-3y-z=0 (1)求x:y:z 已知X-3Y+Z=0 3X-3Y-4Z=0.则X:Y:Z=? 已知2x-y-z=0,3x+4y-2z=0,则x：y：z=? 已知x+4y-3z=0,4x-5y+2z=0,则x：y：z 已知{x-5y+2z=0 3x-5y-4z=0,求x：y:z 已知方程组4x-5y+2z=0 x+2y=3z 则x:y:z 已知x/3=y/4=z/6≠0,求x+y-z/x-y+z的值 已知x-y/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. 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 已知：4x-5y+2z=0 x+4y-3z=0则：(x*x+y*y+z*z)/(x*y+y*z+z*x)=____. 已知 (x+y-z)/z=(x-y+z)/y=(y+z-x)/x,且xyz≠0,求代数式 ((x+y)(y+z)(x+z))/xyz 分式加减法：已知x+y/z=x+z/y=y+z/x(x+y+z≠0）,求x+y-z/x+y+z