x+y+z=0 求证：(x^2-y^2)+(xz-yz)=0

x>=y>=z>0,求证：x^2*y/z+y^2*z/x+z^2*x/y>=x^2+y^2+z^2 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,xyz(x+y+z)=1,求证（x+y）(x+z)>=2 (z-x)^2-4(x-y)(y-z)=0求证x+z-2y=0_ 若(z-x)的二次方-4(x-y)(y-z)=0,求证x-2y+z=0 已知(x-z)^2-4(x-y)(y-z)=0,求证：2y=x+z 若x-2y+z=0 求证（x-z）^2-4(x-y)(y-x)=0 实数x,y,z满足（x-z)的平方减4（x-y)（y-z）=0求证z+x-2y=0 已知三个实数x,y,z满足条件(z-x)^2-4(x-y)(y-z)=0,求证:x,y,z成等差数列 x,y,z∈(0,1),且x+y+z=2,求证1 X/(Y-Z)+Y/(Z-X)+Z/(X-Y)=0求证X/(Y-Z)^2+Y/(Z-X)^2+Z/(X-Y)^2=0通过上面求证下面^2是……的2次方X/(Y-Z)^2+Y/(Z-X)^2+Z/(X-Y)^2=0 已知：x^2/(z+y)+y^2/(x+z)+z^2/(x+y)=0,求x/(z+y)+y/(x+z)+z/(x+y)的值. x^2/(z+y)+y^2/(x+z)+z^2/(x+y)=0,求x/(z+y)+y/(x+z)+z/(x+y)的值 已知x+y+z=0求证x*x*x+y*y*y+z*z*z=3xyz 若xyz=1,求证 x^2/(y+z)+y^2/(z+x)+z^2/(x+y)≥3/2 x,y,z是实数,且x^2+y^2+z^2=2,求证：x+y+z 若x>y>z>0,求证：x-z+27/[(x+z)y-xz-y^2]≥9