通分:x/x²-1,2/x²-2x+1

问题描述:

通分:x/x²-1,2/x²-2x+1

x/x²-1=x/(x+1)(x-1)=x(x-1)/(x+1)(x-1)²
2/(x²-2x+1)=2/(x-1)²=2(x+1)/(x+1)(x-1)²