分解因式x^2+3xy-10y^2-x+9y-26x^2-15y^2-6z^2-xy-5xz+21yz

(2X+Z-Y)/(X^2-XY+XZ-YZ)-(Y-Z)/(X^2-XY-XZ+YZ) 求(2X+Z-Y)/(X^2-XY+XZ-YZ)-(2X+Y+Z)/(X^2+XY+XZ+YZ) 化简(2x-y-z/x^2-xy-xz+yz)+(2y-x-z/y^2-xy-yz+xz)+(2x-x-y/z^2-xz 设x,y,z∈R+,xy+yz+xz=1,证明不等式:(xy)^2/z+(xz)^2/y+(yz)^2/x+6xyz≥x 解方程组（x+y)/xy=5/6,(y+z)/yz=-2/3,2(x+3)+xz=0 xy／x+y＝1,yz／y＋z＝2,xz／x＋z＝3求x,y 如果3y=x+2y,那么x *x+9*y*y+4*z*z-6xy-12yz+4xz的值是多少? x／3=y／2＝z／5,求xy+yz+xz／x²+y²+z² 2^x=5^y=10^z证明xy=xz+yz 2^x=5^y=10^z证明xy=xz=yz 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) 如果1=xy/x+y,2=yz/y+z,3=xz/x+z,则x的值?