若x+y=y+z=z+x=2013,则x+y+z=__________.

(x+y-z)(x-y+z)= 若x+y+z=3y=2z,则x/x+y+z=? 若x,y,z成等差数列,则(z-x)^2-4(x-y)(y-z)= 若z分之x+y+z=y分之x-y+z=x分之-x+y+z,求xyz分之(x+y)(y+z)(z+x) X+Y+Z=? x/y=(x+z)/(y+z)y/z=(x+y)/(x+z) 若X/10=Y/8=Z/9则X+Y+Z/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+y=y+z=z+x=2013,则x+y+z=__________. 若x,y,z成等差数列,则(z-x)^2-4(x-y)(y-x)= (y+z)/x=(z+x)/y=(x+y)/z求x+y-z/x+y+z的值 z+=x>y?++x: 已知(y+z)/x=(z+x)/y=(x+y)/z,则(y+z)/x的值是多少 若xy-z=0,且(y+x)/x=(z+x)/y=(y+x)/z,求[(y+z)(z+x)(x+y)]/xyz的值? 若xy-z不等于0,且(y+x)/x=(z+x)/y=(y+x)/z,求[(y+z)(z+x)(x+y)]/xyz的值? 用行列式的性质证明：y+z z+x x+y x y z x+y y+z z+x =2 z x y z+x x+y y+z y z x 这个怎么证? fangchengzu:X+Z=Y 7Z=X+Y+Z X+Y+Z=14 x=y; y=z; z=x/y