已知方程组{x-2y+4z=0,2x+3y-13z=0,且xyz≠0,求代数x+y+z/x+y-z的值

已知方程组{x-2y+4z=0,2x+3y-13z=0,且xyz≠0,求代数x+y+z/x+y-z的值 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 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) 已知方程组{2X-Y+3Z=0,X-3Y+Z=0(XYZ≠0),求3Y分之4X+2Z的值 已知XYZ满足方程组 X+Y-Z=6 Y+Z-X=2 Z+X-y=0 求X Y Z的值 已知x+y-z/z=x-y+z/y=-x+y+z/x,且xyz不等于0,求分式[(x+y)(x+z)(y+z)]/xyz 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xyz不等于0,且x+2y-z=0,7x-y-z=0,求x+y+z/2x-y-z的值. 已知xyz满足方程组x+4y-3z=0,求x：y：z的值 4x-5y+2z=0 已知方程组x-3y-2z=0 2x-y+z=0 且xyz≠0,求x：y：z 若xyz不等于0,且满足(y+z)/x=(x+z)/y=(x+y)/z,求（y+z)（x+z)（x+y)/xyz的值 若xyz不等于0,且(y+z)/x=(z+x)/y=(x+y)/z,求(y+z)(z+x)(x+y)/xyz的值?