计算2/3x-2/x+y(x+y/3x-x-y)/x-y/x

问题描述:

计算2/3x-2/x+y(x+y/3x-x-y)/x-y/x

原式=[2/3x-2(x+y)(1/3x-1)/(x+y)]*x/(x-y)
=[2/3x-(2/3x-2)]*x/(x-y)
=2x/(x-y)