1.通分:1和1/x-1
(X-1)/(X-1), 1/毁顷侍(X-1)
2.已知1/x-1/乎如y=3,则(纤吵Y-X)=3XY
(2x+3xy-2y)/(x-2xy-y)=(-6XY+3XY)/(-3XY-2XY)
=3/5
1和1/芦肢x-1
通分碰哗埋:(x-1)/(x-1),1/(x-1) (x≠1)
1/x-1/y=3
(y-x)/xy=3
y-x=3xy
x-y=-3xy
(2x+3xy-2y)/(x-2xy-y)
=(2x-2y+3xy)/笑蚂(x-y-2xy)
=[2*(-3xy)+3xy]/(-3xy-2xy)
=-3xy/(-5xy)
=3/5