若xy分之y减x等于3,求分x减2xy减y分之2x加3xy减2y
问题描述:
若xy分之y减x等于3,求分x减2xy减y分之2x加3xy减2y
答
(y-x)/xy=3求(2x+3xy-2y)/(x-2xy-y) ?
(y-x)/xy=3-->1/x- 1/y=3-->y-x=3xy
(2x+3xy-2y)/(x-2xy-y)
=(x-y)/(-5xy)
=3/5