(x+1)分之1+(x-1)分之1+(x²-2x+1)分之1 公分母为：(x+1)(x-1)²=[(x+1)(x-1)²]分之(x-1)²+[(x+1)(x-1)²]分之[(x+1)(x-1)]+[(x+1)(x-1)²]分之(x+1)=[(x+1)(x-1)²]分之[(x-1)²...