已知y-x-2xy=0,求(3x+xy-3y)\(y-xy-x)的值

已知y-x-2xy=0,求(3x+xy-3y)\(y-xy-x)的值
已知y-x-2xy=0,求(3x+xy-3y)\(y-xy-x)的值

已知y-x-2xy=0,求(3x+xy-3y)\(y-xy-x)的值
y-x-2xy=0
所以x-y=-2xy
y-x=2xy
所以原式=[3(x-y)+xy]\[(y-x)-xy]
=[3×(-2xy)+xy]\(2xy-xy)
=-5xy\xy
=-5

785