请看下面的拿宴正漏图消清银片
通分,分母为碧销猛斗樱(x-1)(x+1),则分子为(x+3)+(x+3)(x+1)+(x-1)=x^2+6x+5约掉x+1后变为(x+5)/(x-1) 将x=3 代入=8/悔桥2=4