已知x:3=y:4=z:5(x,y,z不等于零),求(x+y+z):(x+y-z)的比值.
已知x,y,z满足{4x-3y-3z=0,x-3y+z=0.(x不等于0,y不等于0,z不等于0)求x/z和y/z的值
x分之y+z=y分之z+x=z分之x+y(x+y+z不等于0),求x+y+z分之x+y-z
已知x=3y,z=7x(x不等于零)求2x+3y-z分之x+y+z=?
已知x::y:z=3:4:5,(1)求x+y分之z的值;(2)若x+y+z=6,求x,y,z.
已知3X=5Y ,4Y=5Z,求:(1) Y与Z的比值 (2) x:y:z
已知2x+3y-4z=0,3x+4y+5z=0,求x+y+z/(除以)x-y+z的值.
已知方程组4x-3y-3z=0 x+3y+z=0(xyz不等于0),求x/y y/z的值
已知x+y-7z=0 x-2y+5z=0(xyz不等于0),求x+2y-z/y-2x+12z
已知3/x+y=4/x+y=5/y+z,求xyz/(x+y)(y+z)(z+x)的值
已知x=3y,z=7x(x不等于0),求代数式2x+3y-z分之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X Y Z满足3x-2y+z的绝对值+2x+y+2z的绝对值=0(x,y,z不等于0),求x+y除以Z的值