已知x+y/3=y-3z/2=x+3z/5且x+y+z=14则2x+3y-5z=我认为这道题有问题

已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z 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+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. 已知x,y,z 大于0,x+y+z=2,求证 xz/y(y+z)+zy/x(x+y)+yx/z(z+x)大于等于2/3 已知x+y+z=0求证x*x*x+y*y*y+z*z*z=3xyz 试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) 已知x/y+z=y/x+z=z/x+y,分式(x+2y+3z)/(2x+5y-2c)有意义时的值 已知z、y、z同时满足x+3y-5z=0,2x-y-3z=0,求x:y:z 已知x/2=y/3=z/4,则2x+y-z/3x-2y+z=? 已知：x+2y-3z=0,3x-2y+z=0,则x：y：z= 已知(x+2y)/2=(y+3z)/3=(z+4x)/4,则x:y:z=? 已知{x-3y+2z=0 3x-3y-4z+0,则x:y:z=? 已知(x+2y)/3=(y+3z)/4=(z+5x)/5,则x:y:z= 已知x+2y/3=y+3z/4=z+5x/5,则x:y:z=? 已知x+2y/3=y+3z/4=z+5x/5,则x:y:z= 已知x-2y+3z=0,x-3y+4z=0,则x:y:z= 已知 3x-y+2z=0 2x+y-3z=0,求x :y :z.