x²+4x+4/x²-4 - x/x-2,做下吧.
问题描述:
x²+4x+4/x²-4 - x/x-2,做下吧.
答
由(x²+4x+4)/(x²-4)-x/(x-2)
=(x+2)²/(x+2)(x-2)-x/(x-2)
=(x+2)/(x-2)-x/(x-2)
=2/(x-2).