已知x+y/9=3,y+z/9=3,求z+x/9的值

已知｛2x-y-z=0,3x-9y+z=0求1,x:y:z 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/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. 已知:2X-3y+2z=0,x+4Y-9/2z=0求:X:Z的值.X:y:Z的值.X+2y+X/X+y+Z的值. 已知:2X 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 已知实数x,y,z,满足x+y=5,z²=xy+y=9,求x+2y+3Z的值 已知x,y,z满足x+y=5,z^2=xy+y-9 求x+2y+3z的值 已知实数x,y,z满足x-y=5,z^2=-xy-y-9,求x-2y+3z的值 已知x y z 满足x+y=5,z²=xy+y-9,求x+2y+3z的值 (x+y):(y+z):(z+x)=3:4:5 3x+y-z=-4已知(x+y):(y+z):(z+x)=3:4:5 ；3x+y-z=-4求x y z 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)=? 已知3X=4X,5Y=6Z求X+Y：Y+Z 已知z、y、z同时满足x+3y-5z=0,2x-y-3z=0,求x:y:z 已知x+y/2=y+z/3=z-2x/4=k,且知道x+2y-z=9,求k的值 已知x+y/2=y+z/3=z-2x/4=k,且知道x+2y-z=9,求k的值 已知,x,y,z同时满足2x+3y=8,9y+2z=0,x-z=-2,求xyz的值 已知x+y+z=5,2x+3y-z=9,求代数式7x+10y-2z的值