(x-3)/(x+1)(x-1)=A/(x+1)+B/(x-1)化简这个式子可得(x-3)/(x+1)(x-1)=A(x-1)/(x+1)(x-1)+B(x+1)/(x+1)(x-1)由于分母相同,所以只看分子 ,继续化简可得x-3=(A+B)x+(B-A)所以可以得到两个关于A和B的式子,A+B=1 B-A=-3所...