∵x分之1-y分之1=3
∴y-x=3xy 两边同时乘以xy
∴ x-y=-3xy
2x-3xy-2y分之3x-14xy-3y
=[2(x-y)-3xy]/[3(x-y)-14xy]
=(-6xy-3xy)/(-9xy-14xy)
=9/23