若x=1,y=2,z=3,则z+=++x+y++的值是?为什么?

若x+y+z=3y=2z,则x/x+y+z=? 若|x+3|+|y-2|+|2×z+1|=0求(x×z-y×z)(y-x+z)的值 若x:y:z=3:2:1,则x+2y-z/2x-y+z= 若x,y,z成等差数列,则(z-x)^2-4(x-y)(y-z)= 已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z 试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) 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 x+y+z=6 x+2y+3z=14 y+1=z X/10=Y/8=Z/9,则X+Y+Z/2Y-3Z 三元一次方程组题目x+y-z=11 y+z-x=5 x-y+z=1x+y=4 y+z=3 x+z=5若已知x-3y+2z=0 2x+3y-8z=0, 且xyz≠0,则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)=? 若x/2=y/3=z/4,则3x-2y+5z/x+y+z= 若x/3=y/2=z/5,则2x-3y-z/x-y+z= 若方程组2x+3y-z=0,x-3y-z=0,则x：y：z=? 若方程组：x+y-2z=0,3x+y-z=0,则x：y：z= 若2x=3y=5z,则3x-2y+z/x+y-z 若xyz=1,求证 x^2/(y+z)+y^2/(z+x)+z^2/(x+y)≥3/2