已知X分之1减于Y分之1等于4,试求x-3xy-y

已知X分之1减于Y分之1等于4,试求x-3xy-y分之3X+5xy-3y的值?

1个回答

1/x-1/y=4 (y-x)/xy=4 x-y=-4xy
(3X+5xy-3y )/ ( x-3xy-y)
=[3(x-y)+5xy]/[(x-y)-3xy]
=(-12xy+5xy)/(-4xy-3xy)
=1