若x/4=y/4=z/5,则x+y/x-2y+3z=

若x,y,z成等差数列,则(z-x)^2-4(x-y)(y-z)= 若x,y,z成等差数列,则(z-x)^2-4(x-y)(y-x)= 若3x+7y+z=5,4x+10y+z=3,则x+y+z=? 若x/2=y/3=z/4,则3x-2y+5z/x+y+z= 若4x=7y+5z,2x+y=z,则x:y:z的值为 若x+y:y+z:z+x=3:4:5,则x:y:z=?(急,) 若x/2=y/3=z/4则3x-2y+5z/x+y+x= 已知x:4=y:5=z:6.则x:y:z= (x+y):(y+z)= 若x-4y+5z=2,5x+4y+z=4,则x+y= 若x/4=y/4=z/5,则x+y/x-2y+3z= 若x/3=y/4=z/5则x+y/x-2y+3z=? 若2x+5y+4z=0 ,3x+y=0；则x+y-z=? 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= 若{3x-4y=0,5x=4z,则x分之x+y+z=? 已知：4x-5y+2z=0 x+4y-3z=0则：(x*x+y*y+z*z)/(x*y+y*z+z*x)=____. x+y+z=4x-5y=y-x+6z,xyz不等0,x:y:z=? (4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? X/4=Y/5=Z/7则x+y+z/z=?