x/10=y/8=z/9,求(x+y+z)/(x+y)?

x y z x+y--- = --- = ---- ----y+Z z+x x+y ,求 z 的值 .求 x+y---- (x+y-z)(x-y+z)= x/10 = y/8 =z/9 求x+2y+3z/y-5z 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 若z分之x+y+z=y分之x-y+z=x分之-x+y+z,求xyz分之(x+y)(y+z)(z+x) y+z÷x=Z+X÷y=X+Y÷z,X+Y+Z不等0求X+Y-Z÷X+Y+z值 (x+y-z)/z=(y+z-x)/x=(z+x-y)/y 求(x+y)(y+z)(z+x)/xyz 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+y-z)/z=(x-y+z)/y+(y+z-x)/x,且xyz≠0,求代数式[(x+y)(y+z)(x+z) (x-2y+z)/9=(2x+y+3z)/10=-(3x+2y-4z)/3=1 连等,求x,y,z, X+Y+Z=? 若整数x,y,z满足(15/8)^x*(16/9)^y*(27/10)^z=16,求(7x+y)/(z-y)的值.