(x+y-z)(x-y+z)-(x+y+z)(x-y-z)
①(x+y+z)(-x+y+z)(x-y+z)(x+y-z)
x分之y+z=y分之z+x=z分之x+y(x+y+z不等于0),求x+y+z分之x+y-z
(x-y+z)(x+y+z)等于多少.
(x+y+z)*(-x+y+z)*(x-y+z)*(x+y-z)=
计算:(x+y+z)(-x+y+z)(x-y+z)(x+y-z).
1.设X ,Y,Z 成等差数列,代数式(X-Z)*(X-Z)+ 4(X-Y)(Z-Y)=
x,y,z为正实数 x/(2x+y+z)+y/(x+2y+z)+z/(x+y+2z)
(x+y-z)(x-y+z)=
1998(z-y)+1999(y-z)+2000(z-x)=0 1998²(z-y)+1999²(y
已知X*Y*Z不等于0,(Z+Y)/X=(X+Z)/Y=(X+Y)/Z,求(Z+Y)(X+Z)(X+Y)/XYZ的值
证明:(y+z-2x)3+(z+x-2y)3+(x+y-2z)3=3(y+z-2x)(z+x-2y)(x+y-2z).
z分之x+y等于y分之x+z等于x分之y+z(x+y+z不等于零)求x+y+z分之x+y-z的值