x＋y＋z=24 x=y＋2 x＋y=z

x-y/(z-x)(z-y) 一y-z/(x-y)(x-z) ＋z-x/(y-z)(y-x) 2分之一(x+y+z)的平方＋2分之一（x-y-z)(x-y+z)-z(x+y),其中x-y=6,xy=21 x＋y＋z=24 x=y＋2 x＋y=z (x+y-z)(x-y+z)= 1/x+1/y＋1/z=1.x,y,z,属于不同自然数 y, 若x,y,z满足x分之y+z=y分之z＋X＝z分之x＋y＝k,求k 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) 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^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 X+Y+Z=? x/y=(x+z)/(y+z)y/z=(x+y)/(x+z) 已知实数x、y、z满足x＋y=5,z的平方=xy+y-9,那么x+2y+3z=( ) 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)=? 如果x=3y,z=x/2,那么(x－y＋z/x＋y＋z)等于几? 已知x平方+ y平方+z平方减2z+4y+6z+14=0,求x＋y＋z的直