xy/x-z-xy/y-z 分式化简

一道初二分式计算题(2X+Z-Y)/(X^2-XY+XZ-YZ)-(2X+Y+Z)/(X^2+XY+XZ+YZ) 因式分解：x^-4xy+4y^-z^ x+y+z=0,2x-y-7z=0,求分式3xy-4z的平方除以x的平方-y的平方 分式题:xy=x+y,yz=2(y+z),zx=3(z+x),求xyz/(xy+yz+xz) (1/x+1/y+1/z)×(xy)/(xy+yz+zx) (2X+Z-Y)/(X^2-XY+XZ-YZ)-(Y-Z)/(X^2-XY-XZ+YZ) 化简(y-x)(z-x)/(x-2y+z)(x+y-2z)+（z-y)(x-y)/(xy-2z)(y+z-2x)+(x- x y z 满足等式x/4=y/3=z/2不等于0,求分式x二次方+y二次方/xy-xz的值 设xyz是非零实数求|x|/x+|y|/y+|z|/z+|xy|/xy+|xz|/xz+|yz|/yz+|xyz|/xy 若x分之1-y分之1=3,则分式x-2xy-y分之2z+3xy-2y的值为 z=ln sin(xy) 则 z'y=x cot(xy).判断这题对错. 1.x-z/xy - 2ab/xy