已知x+9/y=3, y+1/z=3, 则z+1/x的值是?9/y 1/z 1/x 是分式,其他是相加

已知｛2x-y-z=0,3x-9y+z=0求1,x:y:z 已知x-y/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. 已知实数x y z满足x/(x+1)=y/(y+2)=z/(z+3)=(x+y+z)/3,求x+y+z的值 已知实数x y z满足x/(x+1)=y/(y+2)=z/(z+3)=(x+y+z)/3,求x+y+z的值 已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z 已知X：Y=0.3：1/2,Y：Z=2：3,求X：Y：Z 已知x:y=3:5 y:z=6:1,求x:y:z( ):( ):( ) 已知x+y+z=0求证x*x*x+y*y*y+z*z*z=3xyz 已知 x/(y+z)+y/(z+x)+z/(x+y)=1求 (x*x)/(y+z)+(y*y)/(x+z)+(z*z)/(x+y)=? 一条分式数学题已知x y z满足x/x+y + y/z+x + z/x+y =1,求x²/x+y + y²/z+x + z²/x+y的值.3Q 已知4x-3y-3z=0 x-3y-z=0 (1)求x:y:z 已知x:y:z=1:3:5,求（2x+3y-z)/(x+y-2z)的值 已知{x：y：z=1：2：3,x+y+z=12,求x、y、z的值 已知x:y:z=1:2:3,x+y+z=24,求x,y,z 已知（1）X-Y+Z=0 (2)X+2Y-3Z=0 求X:Y:Z 已知xyz≥0,x+y+z=1,化简x（2y-z）/(1+x+3y)+y(2z-x) /(1+y+3z) +z(2x-y)/(1+z+3x) 已知实数xyz满足x/(x+1)=y/(y+2)=z/(z+3)=(x+y+z)/3求x+y+z的值 已知x+1/y=y+1/z=z+1/x,求证y/x+z/y+x/z=3 ,