若x+y+z=2,x^2-（y+z）^2=8,则x-y-z=多少?

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)= 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? (x-2y+z)(x+y-2z)分之（y-x)(z-x) + (x+y-2z)(y+z-2x)分之(z-y)(x-y) + (y+z-2z)(x-2y+z)分之（x-z)(y-z)=?第三部分那个是 （y+z-2x)(x-2y+z)分之（x-z)(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^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)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z 若x+y+z=2,x^2-（y+z）^2=8,则x-y-z=多少? 若（z-x）^2-4(x-y)(y-z)=0,试说明:x-2y+z=0 若(z-x)^2-4（x-y）（y-Z)=0,试说明x-2y+z=0. 若|x+3|+|y-2|+|2×z+1|=0求(x×z-y×z)(y-x+z)的值 已知x:：y：z=3：4：5,(1)求x+y分之z的值；（2）若x+y+z=6,求x,y,z. 化简(y-x)(z-x)/(x-2y+z)(x+y-2z)+（z-y)(x-y)/(x-2z+y)(y+z-2x)+(x-z)(y-z)/(y+z-2x)(x-2y+z) 计算:(y-x)(z-x)/(x-2y+z)(x+y-2z)+(z-y)(x-y)/(x+y-2z)(y+z-2x)+(x-z)(y-z)/(y+z-2x)(x-2y+z) （x-2y+z）（-x+2y+z） x+2y-z）（x+2y-z） (x+y-z)^2-(x-y+z)^2=?