数学题(x-y)/(y-z),(y-z)/(z-x),(z-x)/(x-y)已知有理数X,Y,Z两两不相等,则(x-y)/(y-z),(y-z)/(z-x),(z-x)/(x-y)中负数的个数是（）A.1个 B.2个 C.3个 D.0个或2个

把年级数学题x+y/(x-y)(y-z)+x+z/(y-x)(y-z) x-y/(z-x)(z-y) 一y-z/(x-y)(x-z) ＋z-x/(y-z)(y-x) x^-(y-z)^/(x+y)^-z^ 计算（x+y-z)(x-y-z) 计算：(x-y+z)(-x+y+z) (x+y-z)(x-y+z)= x y y ...y z x y ...y z z x ...y ........z z z ...x 求解行列式. x/y>0,y/z 求数学题X+Y=0.55 X+Z=0.45 Y+Z=0.5,求X,Y Z x+y>z 0 用乘法公式计算(x+y)(x-y)+(-y-z)(-y+z)+(-x+z)(z+x) 计算：（X+y+z)(-x+y+z)(x-y+z)(x+y-z) （x+y-z）（x-y+z）-（x+y+z）（x-y-z） 因式分解 ：（x+y-z)(x-y-z)+(y-x+z)(y-x-z) 因式分解测试题x(x+y-z)+y(x+y-z)+z(z-x-y) (x+y+z)(-x+y+z)(x-y+z)(x+y-z)等于什么? (x-y+z)² （x+y-z）*（x+y-z)-(x-y+z)*(x-y-z)等于多少