己知x+2y/3=y+3z/4=z+5x/5则x:y:z=__________

己知x+2y-3z=0,2x+3y+5z=0,求x+y+z/x-y+z的值. 己知x+2y/3=y+3z/4=z+5x/5则x:y:z=__________ 己知x=2,y+z=1,求代数式x2(-y-z)+4x(z+y)的值. 己知x/2=y/3=z/4,求xy+yz+zx/5x的平方+3y的平方+z的平方的值 己知3元齐次线性方程组3x+2y-z=0 kx+7y-2z=0 2x-y+3z=0有非零解k (4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? x/2=y/3=z/5 x+3y-z/x-3y+z x+y/2=z+x/3=y+z/4 x+y+z=27 x+2y=3x+2z=4y+z 求x:y:z 设|x|-|y|+|z|=|x+y+z|,且|x+y|=4,|y+z|=5,|y|=3,求(x-y-z)^2的值 (4x-2y-z)-{5x-[8y-2z-(x+y)]-2(3y-10z)}=?好难啊 x+y=5 2x+3y-z=9 x-y+z=4 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x-y/x+y=y+z/2(y-z)=z+x/3(z-x),求证8x+9y+5z=0THX.. 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):(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 2x+z=10 x+y-z=4 3x-y-z=0