a＞b＞c,x＞y＞z,M=ax+by+cz,N=az+by+cx,P=ay+bz+cx,Q=az+bx+cy,则[ ]A．M＞P＞N且M＞Q＞N. B．N＞P＞M且N＞Q＞MC．P＞M＞Q且P＞N＞Q. D．Q＞M＞P且Q＞N＞P

已知ax^3=by^3=cz^3,三次根号(ax^2+by^2+cz^2)=三次根号a+三次根号b+三次根号c,xyz＞0求(1/x+1/y+1/z)的值已知ax^3=by^3=cz^3,三次根号(ax^2+by^2+cz^2)=三次根号a+三次根号b+三次根号c,xyz＞0 求(1/x+1/y+1/z)的值（注 a/x*x-yz=b/y*y-zx=c/z*z-xy求证ax+by+cz=(x+y+z)*(a+b+c) ax+bx+cx=(a+b+c)x,ay+by+cy=(a+b+c)y,az+bz+cz=(a+b+c)z,xm+ym+zm=(x+y+z)m,求m的值 a＞b＞c,x＞y＞z,M=ax+by+cz,N=az+by+cx,P=ay+bz+cx,Q=az+bx+cy,则[ ]A．M＞P＞N且M＞Q＞N. B．N＞P＞M且N＞Q＞MC．P＞M＞Q且P＞N＞Q. D．Q＞M＞P且Q＞N＞P 已知a,b,c,x,y,z为正实数,求证ax/(a+x)+by/(b+y)+cz/(c+z) 已知ax+by+cz=m(各字母均大于0).求x^2 +y^2 +z^2的最小值（用a,b,c,m表示）. 设x=by+cz,y=cz+ax,z=ax+by,求(a/a+1)+(b/b+1)+(c/c+1)的值 设x-by+cz,y=cz+ax,z=ax+by,求a/a+1+b/b+1+c/c+1的值. a/x^2-yz=b/y^2-zx=c/z^2-xy xyz=0 求证ax+by+cz=(a+b+c)(x+y+z) a^2+b^2+c^2=25 x^2+y^2+z^2=36 ax+by+cz=30 (a+b+c):(x+y+z)=? 若a/x^2-yz=b/y^2-zx=c/z^2-xy,求证ax+by+cz=(a+b+c)(x+y+z) (x^2+y^2+z^2)(a^2+b^2+c^2)=(ax+by+cz)^2 求证x/a=y/b=z/c 不等式应用：已知a*a+b*b+c*c=1,x*x+y*y+z*z=9.那么ax+by+cz的最大值是? 已知y+z/ay+bz=z+x/az+bx=x+y/ax+by=m,求证：m=2/a+b ．已知a,b,c,x,y,z都是非零实数,且a^2+b^2+c^2=x^2+y^2+z^2=ax+by-cz,求证:x/a=y/b=z/c 设a,b,c,x,y,z,都是正数,且a^2+b^2+c^2=25.,x^2+y^2+z^2=36,ax+by+cz=30.求（a+b+c）/(x+y+z) 设a,b,c,x,y,z属于R,且a^2+b^2+c^2=25 x^2+y^2+z^2=36,ax+by+cz=30求(a+b+c)/(x+y+z) 若a>b>c 且x>y>z 如何证明ax+by+cz>ay+bz+cx?