化简分式x²+x/x²-1 x²-9/x²-6x+9
问题描述：
化简分式x²+x/x²-1 x²-9/x²-6x+9
答
x²+x/x²-1
=x(x+1)/(x+1)(x-1)
=x/(x-1)
x²-9/x²-6x+9
=(x+3)(x-3)/(x-3)²
=(x+3)/(x-3)